EFM8 Sleepy Bee Family
EFM8SB1 Data Sheet
The EFM8SB1, part of the Sleepy Bee family of MCUs, is the
world’s most energy friendly 8-bit microcontrollers with a compre-
hensive feature set in small packages.
These devices offer lowest power consumption by combining innovative low energy tech-
niques and short wakeup times from energy saving modes into small packages, making
them well-suited for any battery operated applications. With an efficient 8051 core, 14
high-quality capacitive sense channels, and precision analog, the EFM8SB1 family is al-
so optimal for embedded applications.
EFM8SB1 applications include the following:
ENERGY FRIENDLY FEATURES
• Lowest MCU sleep current with supply
brownout (50 nA)
• Lowest MCU active current (150 μA / MHz
at 24.5 MHz)
• Lowest MCU wake on touch average
current (< 1 μA)
• Lowest sleep current using internal RTC
and supply brownout (< 300 nA)
• Ultra-fast wake up for digital and analog
peripherals (< 2 μs)
• Integrated LDO to maintain ultra-low
active current at all voltages
• Touch pads / key pads
• Wearables
• Instrumentation panels
• Battery-operated consumer electronics
SecurityAnalog Interfaces
Comparator 0
Internal Voltage
Reference
Internal Current
Reference
ADC
Capacitive Sense
I/O Ports
Core / Memory Clock Management
CIP-51 8051 Core
(25 MHz)
Energy Management
Internal LDO
Regulator
Brown-Out Detector
Power-On Reset
8-bit SFR bus
Serial Interfaces Timers and Triggers
SPI Pin Reset Timers
0/1/2/3 PCA/PWM
Watchdog
Timer
16-bit CRC
Flash Program
Memory
(up to 8 KB)
RAM Memory
(up to 512 bytes)
Debug Interface
with C2
Lowest power mode with peripheral operational:
IdleNormal Suspend Sleep
High Frequency
24.5 MHz RC
Oscillator
Pin Wakeup
External
Interrupts
General
Purpose I/O
I2C / SMBus
UART
Low Frequency
RC Oscillator
External 32 kHz RTC Oscillator
Low Power 20 MHz
RC Oscillator
External
Oscillator
Real Time
Clock
silabs.com | Building a more connected world. Rev. 1.4
1. Feature List
The EFM8SB1 highlighted features are listed below.
• Core:
• Pipelined CIP-51 Core
• Fully compatible with standard 8051 instruction set
• 70% of instructions execute in 1-2 clock cycles
• 25 MHz maximum operating frequency
• Memory:
• Up to 8 kB flash memory, in-system re-programmable
from firmware.
• Up to 512 bytes RAM (including 256 bytes standard 8051
RAM and 256 bytes on-chip XRAM)
• Power:
• Internal LDO regulator for CPU core voltage
• Power-on reset circuit and brownout detectors
• I/O: Up to 17 total multifunction I/O pins:
• Flexible peripheral crossbar for peripheral routing
• 5 mA source, 12.5 mA sink allows direct drive of LEDs
• Clock Sources:
• Internal 20 MHz low power oscillator with ±10% accuracy
• Internal 24.5 MHz precision oscillator with ±2% accuracy
• Internal 16.4 kHz low-frequency oscillator or RTC 32 kHz
crystal (RTC crystal not available on CSP16 packages)
• External crystal, RC, C, and CMOS clock options
• Timers/Counters and PWM:
• 32-bit Real Time Clock (RTC)
• 3-channel Programmable Counter Array (PCA) supporting
PWM, capture/compare, and frequency output modes with
watchdog timer function
• 4 x 16-bit general-purpose timers
• Communications and Digital Peripherals:
• UART
• SPI™ Master / Slave
• SMBus™ / I2C™ Master / Slave
• 16-bit CRC unit, supporting automatic CRC of flash at 256-
byte boundaries
• Analog:
• Capacitive Sense (CS0)
• Programmable current reference (IREF0)
• 12-Bit Analog-to-Digital Converter (ADC0)
• 1 x Low-current analog comparator
• On-Chip, Non-Intrusive Debugging
• Full memory and register inspection
• Four hardware breakpoints, single-stepping
• Pre-loaded UART bootloader
• Temperature range -40 to 85 ºC
• Single power supply 1.8 to 3.6 V
• QSOP24, QFN24, QFN20, and CSP16 packages
With on-chip power-on reset, voltage supply monitor, watchdog timer, and clock oscillator, the EFM8SB1 devices are truly standalone
system-on-a-chip solutions. The flash memory is reprogrammable in-circuit, providing non-volatile data storage and allowing field up-
grades of the firmware. The on-chip debugging interface (C2) allows non-intrusive (uses no on-chip resources), full speed, in-circuit
debugging using the production MCU installed in the final application. This debug logic supports inspection and modification of memory
and registers, setting breakpoints, single stepping, and run and halt commands. All analog and digital peripherals are fully functional
while debugging. Each device is specified for 1.8 to 3.6 V operation. Devices are AEC-Q100 qualified (Grade 3) and are available in 16-
pin CSP, 20-pin QFN, 24-pin QFN, or 24-pin QSOP packages. All package options are lead-free and RoHS compliant.
Note: CSP devices can be handled and soldered using industry standard surface mount assembly techniques. However, because CSP
devices are essentially a piece of silicon and are not encapsulated in plastic, they are susceptible to mechanical damage and may be
sensitive to light. When CSP packages must be used in an environment exposed to light, it may be necessary to cover the top and
sides with an opaque material.
EFM8SB1 Data Sheet
Feature List
silabs.com | Building a more connected world. Rev. 1.4 | 1
2. Ordering Information
EFM8 SB1 –0 F 8 G A –QSOP24 R
Tape and Reel (Optional)
Package Type
Revision
Temperature Grade G (-40 to +85), A (-40 to +85, Automotive Grade)
Flash Memory Size – 8 KB
Memory Type (Flash)
Family Feature Set
Sleepy Bee 1 Family
Silicon Labs EFM8 Product Line
Figure 2.1. EFM8SB1 Part Numbering
All EFM8SB1 family members have the following features:
• CIP-51 Core running up to 25 MHz
• Three Internal Oscillators (24.5 MHz, 20 MHz, and 16 kHz)
• SMBus / I2C
• SPI
• UART
• 3-Channel Programmable Counter Array (PWM, Clock Generation, Capture/Compare)
• 4 16-bit Timers
• Analog Comparator
• 6-bit current sourc reference
• 12-bit Analog-to-Digital Converter with integrated multiplexer, voltage reference, and temperature sensor
• 16-bit CRC Unit
• AEC-Q100 qualified (Grade 3)
• Pre-loaded UART bootloader
In addition to these features, each part number in the EFM8SB1 family has a set of features that vary across the product line. The
product selection guide shows the features available on each family member.
Table 2.1. Product Selection Guide
Ordering Part
Number
Flash Memory (kB)
RAM (Bytes)
Digital Port
I/Os (Total)
ADC0 Channels
Capacitive
Touch Inputs
Pb-free
(RoHS Compliant)
Temperature Range
Package
EFM8SB10F8G-A-QSOP24 8 512 17 10 14 Yes -40 to +85 C QSOP24
EFM8SB10F8G-A-QFN24 8 512 17 10 14 Yes -40 to +85 C QFN24
EFM8SB10F8G-A-QFN20 8 512 16 9 13 Yes -40 to +85 C QFN20G
EFM8SB10F8G-A-CSP16 8 512 13 9 12 Yes -40 to +85 C CSP16
EFM8SB10F4G-A-QFN20 4 512 16 9 13 Yes -40 to +85 C QFN20G
EFM8SB1 Data Sheet
Ordering Information
silabs.com | Building a more connected world. Rev. 1.4 | 2
Ordering Part
Number
Flash Memory (kB)
RAM (Bytes)
Digital Port
I/Os (Total)
ADC0 Channels
Capacitive
Touch Inputs
Pb-free
(RoHS Compliant)
Temperature Range
Package
EFM8SB10F2G-A-QFN20 2 256 16 9 13 Yes -40 to +85 C QFN20G
EFM8SB10F8A-A-QFN24 8 512 17 10 14 Yes -40 to +85 C QFN24
EFM8SB10F8A-A-QFN20 8 512 16 9 13 Yes -40 to +85 C QFN20A
The A-grade (i.e. EFM8SB10F8A-A-QFN20) devices receive full automotive quality production status, including AEC-Q100 qualifica-
tion, registration with International Material Data System (IMDS), and Part Production Approval Process (PPAP) documentation. PPAP
documentation is available at www.silabs.com with a registered and NDA approved user account.
EFM8SB1 Data Sheet
Ordering Information
silabs.com | Building a more connected world. Rev. 1.4 | 3
3. System Overview
3.1 Introduction
Digital Peripherals
Analog Peripherals
AMUX
UART
Timers 0,
1, 2, 3
PCA/WDT
Priority
Crossbar
Decoder
Crossbar Control
Port I/O Configuration
CIP-51 8051 Controller
Core
8/4/2 KB ISP Flash
Program Memory
256 Byte SRAM
SFR
Bus
256 Byte XRAM
14-Channel
Capacitance
To Digital
Converter
SPI
Comparator
VDD
XTAL1
SYSCLK
System Clock
Configuration
External
Oscillator
Circuit
Precision
24.5 MHz
Oscillator
Debug /
Programming
Hardware
Power On
Reset/PMU
Reset
C2D
C2CK/RSTb
Wake
12-bit
ADC
Temp
Sensor
External
VREF
Internal
VREF VDD
XTAL2
Low Power
20 MHz
Oscillator
6-bit
IREF
VREF
GND
IREF0
RTC / Low
Freq.
Oscillator
XTAL3
XTAL4
GND
VREG Digital
Power
+
-
Port 0
Drivers
Port 1
Drivers
P0.n
Port 2
Driver P2.n
P1.n
CRC
SMBus
Figure 3.1. Detailed EFM8SB1 Block Diagram
This section describes the EFM8SB1 family at a high level. For more information on each module including register definitions, see the
EFM8SB1 Reference Manual.
EFM8SB1 Data Sheet
System Overview
silabs.com | Building a more connected world. Rev. 1.4 | 4
3.2 Power
All internal circuitry draws power from the VDD supply pin. External I/O pins are powered from the VIO supply voltage (or VDD on devi-
ces without a separate VIO connection), while most of the internal circuitry is supplied by an on-chip LDO regulator. Control over the
device power can be achieved by enabling/disabling individual peripherals as needed. Each analog peripheral can be disabled when
not in use and placed in low power mode. Digital peripherals, such as timers and serial buses, have their clocks gated off and draw little
power when they are not in use.
Table 3.1. Power Modes
Power Mode Details Mode Entry Wake-Up Sources
Normal Core and all peripherals clocked and fully operational — —
Idle • Core halted
• All peripherals clocked and fully operational
• Code resumes execution on wake event
Set IDLE bit in PCON0 Any interrupt
Suspend • Core and digital peripherals halted
• Internal oscillators disabled
• Code resumes execution on wake event
1. Switch SYSCLK to
HFOSC0 or LPOSC0
2. Set SUSPEND bit in
PMU0CF
• RTC0 Alarm Event
• RTC0 Fail Event
• CS0 Interrupt
• Port Match Event
• Comparator 0 Rising
Edge
Stop • All internal power nets shut down
• Pins retain state
• Exit on any reset source
Set STOP bit in PCON0 Any reset source
Sleep1• Most internal power nets shut down
• Select circuits remain powered
• Pins retain state
• All RAM and SFRs retain state
• Code resumes execution on wake event
1. Disable unused ana-
log peripherals
2. Set SLEEP bit in
PMU0CF
• RTC0 Alarm Event
• RTC0 Fail Event
• Port Match Event
• Comparator 0 Rising
Edge
Note:
1. Entering Sleep may disconnect the active debug session.
3.3 I/O
Digital and analog resources are externally available on the device’s multi-purpose I/O pins. Port pins P0.0-P1.7 can be defined as gen-
eral-purpose I/O (GPIO), assigned to one of the internal digital resources through the crossbar or dedicated channels, or assigned to an
analog function. Port pin P2.7 can be used as GPIO. Additionally, the C2 Interface Data signal (C2D) is shared with P2.7.
• Up to 17 multi-functions I/O pins, supporting digital and analog functions.
• Flexible priority crossbar decoder for digital peripheral assignment.
• Two drive strength settings for each pin.
• Two direct-pin interrupt sources with dedicated interrupt vectors (INT0 and INT1).
• Up to 16 direct-pin interrupt sources with shared interrupt vector (Port Match).
EFM8SB1 Data Sheet
System Overview
silabs.com | Building a more connected world. Rev. 1.4 | 5
3.4 Clocking
The CPU core and peripheral subsystem may be clocked by both internal and external oscillator resources. By default, the system
clock comes up running from the 20 MHz low power oscillator divided by 8.
• Provides clock to core and peripherals.
• 20 MHz low power oscillator (LPOSC0), accurate to ±10% over supply and temperature corners.
• 24.5 MHz internal oscillator (HFOSC0), accurate to ±2% over supply and temperature corners.
• 16.4 kHz low-frequency oscillator (LFOSC0) or external RTC 32 kHz crystal.
• External RC, C, CMOS, and high-frequency crystal clock options (EXTCLK).
• Clock divider with eight settings for flexible clock scaling: Divide the selected clock source by 1, 2, 4, 8, 16, 32, 64, or 128.
3.5 Counters/Timers and PWM
Real Time Clock (RTC0)
The RTC is an ultra low power, 36 hour 32-bit independent time-keeping Real Time Clock with alarm. The RTC has a dedicated 32 kHz
oscillator. No external resistor or loading capacitors are required, and a missing clock detector features alerts the system if the external
crystal fails. The on-chip loading capacitors are programmable to 16 discrete levels allowing compatibility with a wide range of crystals.
The RTC module includes the following features:
• Up to 36 hours (32-bit) of independent time keeping.
• Support for internal 16.4 kHz low frequency oscillator (LFOSC0) or external 32 kHz crystal (crystal not available on CSP16 pack-
ages).
• Internal crystal loading capacitors with 16 levels.
• Operation in the lowest power mode and across the full supported voltage range.
• Alarm and oscillator failure events to wake from the lowest power mode or reset the device.
• Buffered clock output available for other system devices even in the lowest power mode.
Programmable Counter Array (PCA0)
The programmable counter array (PCA) provides multiple channels of enhanced timer and PWM functionality while requiring less CPU
intervention than standard counter/timers. The PCA consists of a dedicated 16-bit counter/timer and one 16-bit capture/compare mod-
ule for each channel. The counter/timer is driven by a programmable timebase that has flexible external and internal clocking options.
Each capture/compare module may be configured to operate independently in one of five modes: Edge-Triggered Capture, Software
Timer, High-Speed Output, Frequency Output, or Pulse-Width Modulated (PWM) Output. Each capture/compare module has its own
associated I/O line (CEXn) which is routed through the crossbar to port I/O when enabled.
• 16-bit time base.
• Programmable clock divisor and clock source selection.
• Up to three independently-configurable channels
• 8, 9, 10, 11 and 16-bit PWM modes (edge-aligned operation).
• Frequency output mode.
• Capture on rising, falling or any edge.
• Compare function for arbitrary waveform generation.
• Software timer (internal compare) mode.
• Integrated watchdog timer.
EFM8SB1 Data Sheet
System Overview
silabs.com | Building a more connected world. Rev. 1.4 | 6
Timers (Timer 0, Timer 1, Timer 2, and Timer 3)
Several counter/timers are included in the device: two are 16-bit counter/timers compatible with those found in the standard 8051, and
the rest are 16-bit auto-reload timers for timing peripherals or for general purpose use. These timers can be used to measure time inter-
vals, count external events and generate periodic interrupt requests. Timer 0 and Timer 1 are nearly identical and have four primary
modes of operation. The other timers offer both 16-bit and split 8-bit timer functionality with auto-reload and capture capabilities.
Timer 0 and Timer 1 include the following features:
• Standard 8051 timers, supporting backwards-compatibility with firmware and hardware.
• Clock sources include SYSCLK, SYSCLK divided by 12, 4, or 48, the External Clock divided by 8, or an external pin.
• 8-bit auto-reload counter/timer mode
• 13-bit counter/timer mode
• 16-bit counter/timer mode
• Dual 8-bit counter/timer mode (Timer 0)
Timer 2 and Timer 3 are 16-bit timers including the following features:
• Clock sources include SYSCLK, SYSCLK divided by 12, or the External Clock divided by 8.
• 16-bit auto-reload timer mode
• Dual 8-bit auto-reload timer mode
• Comparator 0 or RTC0 capture (Timer 2)
• RTC0 or EXTCLK/8 capture (Timer 3)
Watchdog Timer (WDT0)
The device includes a programmable watchdog timer (WDT) integrated within the PCA0 peripheral. A WDT overflow forces the MCU
into the reset state. To prevent the reset, the WDT must be restarted by application software before overflow. If the system experiences
a software or hardware malfunction preventing the software from restarting the WDT, the WDT overflows and causes a reset. Following
a reset, the WDT is automatically enabled and running with the default maximum time interval. If needed, the WDT can be disabled by
system software. The state of the RSTb pin is unaffected by this reset.
The Watchdog Timer integrated in the PCA0 peripheral has the following features:
• Programmable timeout interval
• Runs from the selected PCA clock source
• Automatically enabled after any system reset
3.6 Communications and Other Digital Peripherals
Universal Asynchronous Receiver/Transmitter (UART0)
UART0 is an asynchronous, full duplex serial port offering modes 1 and 3 of the standard 8051 UART. Enhanced baud rate support
allows a wide range of clock sources to generate standard baud rates. Received data buffering allows UART0 to start reception of a
second incoming data byte before software has finished reading the previous data byte.
The UART module provides the following features:
• Asynchronous transmissions and receptions.
• Baud rates up to SYSCLK/2 (transmit) or SYSCLK/8 (receive).
• 8- or 9-bit data.
• Automatic start and stop generation.
• Single-byte FIFO on transmit and receive.
EFM8SB1 Data Sheet
System Overview
silabs.com | Building a more connected world. Rev. 1.4 | 7
Serial Peripheral Interface (SPI0)
The serial peripheral interface (SPI) module provides access to a flexible, full-duplex synchronous serial bus. The SPI can operate as a
master or slave device in both 3-wire or 4-wire modes, and supports multiple masters and slaves on a single SPI bus. The slave-select
(NSS) signal can be configured as an input to select the SPI in slave mode, or to disable master mode operation in a multi-master
environment, avoiding contention on the SPI bus when more than one master attempts simultaneous data transfers. NSS can also be
configured as a firmware-controlled chip-select output in master mode, or disabled to reduce the number of pins required. Additional
general purpose port I/O pins can be used to select multiple slave devices in master mode.
The SPI module includes the following features:
• Supports 3- or 4-wire operation in master or slave modes.
• Supports external clock frequencies up to SYSCLK / 2 in master mode and SYSCLK / 10 in slave mode.
• Support for four clock phase and polarity options.
• 8-bit dedicated clock clock rate generator.
• Support for multiple masters on the same data lines.
System Management Bus / I2C (SMB0)
The SMBus I/O interface is a two-wire, bi-directional serial bus. The SMBus is compliant with the System Management Bus Specifica-
tion, version 1.1, and compatible with the I2C serial bus.
The SMBus module includes the following features:
• Standard (up to 100 kbps) and Fast (400 kbps) transfer speeds.
• Support for master, slave, and multi-master modes.
• Hardware synchronization and arbitration for multi-master mode.
• Clock low extending (clock stretching) to interface with faster masters.
• Hardware support for 7-bit slave and general call address recognition.
• Firmware support for 10-bit slave address decoding.
• Ability to inhibit all slave states.
• Programmable data setup/hold times.
16-bit CRC (CRC0)
The cyclic redundancy check (CRC) module performs a CRC using a 16-bit polynomial. CRC0 accepts a stream of 8-bit data and posts
the 16-bit result to an internal register. In addition to using the CRC block for data manipulation, hardware can automatically CRC the
flash contents of the device.
The CRC module is designed to provide hardware calculations for flash memory verification and communications protocols. The CRC
module supports the standard CCITT-16 16-bit polynomial (0x1021), and includes the following features:
• Support for CCITT-16 polynomial
• Byte-level bit reversal
• Automatic CRC of flash contents on one or more 256-byte blocks
• Initial seed selection of 0x0000 or 0xFFFF
EFM8SB1 Data Sheet
System Overview
silabs.com | Building a more connected world. Rev. 1.4 | 8
3.7 Analog
Capacitive Sense (CS0)
The Capacitive Sense subsystem uses a capacitance-to-digital circuit to determine the capacitance on a port pin. The module can take
measurements from different port pins using the module’s analog multiplexer. The module can be configured to take measurements on
one port pin, a group of port pins one-by-one using auto-scan, or the total capacitance on multiple channels together. A selectable gain
circuit allows the designer to adjust the maximum allowable capacitance. An accumulator is also included, which can be configured to
average multiple conversions on an input channel. Interrupts can be generated when the CS0 peripheral completes a conversion or
when the measured value crosses a configurable threshold.
The Capacitive Sense module includes the following features:
• Measure multiple pins one-by-one using auto-scan or total capacitance on multiple channels together.
• Configurable input gain.
• Hardware auto-accumulate and average.
• Multiple internal start-of-conversion sources.
• Operational in Suspend when all other clocks are disabled.
• Interrupts available at the end of a conversion or when the measured value crosses a configurable threshold.
Programmable Current Reference (IREF0)
The programmable current reference (IREF0) module enables current source or sink with two output current settings: Low Power Mode
and High Current Mode. The maximum current output in Low Power Mode is 63 µA (1 µA steps) and the maximum current output in
High Current Mode is 504 µA (8 µA steps).
The IREF module includes the following features:
• Capable of sourcing or sinking current in programmable steps.
• Two operational modes: Low Power Mode and High Current Mode.
• Fine-tuning mode for higher output precision available in conjunction with the PCA0 module.
12-Bit Analog-to-Digital Converter (ADC0)
The ADC is a successive-approximation-register (SAR) ADC with 12-, 10-, and 8-bit modes, integrated track-and hold and a program-
mable window detector. The ADC is fully configurable under software control via several registers. The ADC may be configured to
measure different signals using the analog multiplexer. The voltage reference for the ADC is selectable between internal and external
reference sources.
• Up to 10 external inputs.
• Single-ended 12-bit and 10-bit modes.
• Supports an output update rate of 75 ksps samples per second in 12-bit mode or 300 ksps samples per second in 10-bit mode.
• Operation in low power modes at lower conversion speeds.
• Asynchronous hardware conversion trigger, selectable between software, external I/O and internal timer sources.
• Output data window comparator allows automatic range checking.
• Support for burst mode, which produces one set of accumulated data per conversion-start trigger with programmable power-on set-
tling and tracking time.
• Conversion complete and window compare interrupts supported.
• Flexible output data formatting.
• Includes an internal 1.65 V fast-settling reference and support for external reference.
• Integrated temperature sensor.
EFM8SB1 Data Sheet
System Overview
silabs.com | Building a more connected world. Rev. 1.4 | 9
Low Current Comparator (CMP0)
An analog comparator is used to compare the voltage of two analog inputs, with a digital output indicating which input voltage is higher.
External input connections to device I/O pins and internal connections are available through separate multiplexers on the positive and
negative inputs. Hysteresis, response time, and current consumption may be programmed to suit the specific needs of the application.
The comparator module includes the following features:
• Input options in addition to the pins:
• Capacitive Sense Comparator output.
• VDD.
• VDD divided by 2.
• Internal connection to LDO output.
• Direct connection to GND.
• Synchronous and asynchronous outputs can be routed to pins via crossbar.
• Programmable hysteresis between 0 and ±20 mV.
• Programmable response time.
• Interrupts generated on rising, falling, or both edges.
3.8 Reset Sources
Reset circuitry allows the controller to be easily placed in a predefined default condition. On entry to this reset state, the following occur:
• The core halts program execution.
• Module registers are initialized to their defined reset values unless the bits reset only with a power-on reset.
• External port pins are forced to a known state.
• Interrupts and timers are disabled.
All registers are reset to the predefined values noted in the register descriptions unless the bits only reset with a power-on reset. The
contents of RAM are unaffected during a reset; any previously stored data is preserved as long as power is not lost. The Port I/O latch-
es are reset to 1 in open-drain mode. Weak pullups are enabled during and after the reset. For Supply Monitor and power-on resets,
the RSTb pin is driven low until the device exits the reset state. On exit from the reset state, the program counter (PC) is reset, and the
system clock defaults to an internal oscillator. The Watchdog Timer is enabled, and program execution begins at location 0x0000.
Reset sources on the device include the following:
• Power-on reset
• External reset pin
• Comparator reset
• Software-triggered reset
• Supply monitor reset (monitors VDD supply)
• Watchdog timer reset
• Missing clock detector reset
• Flash error reset
• RTC0 alarm or oscillator failure
3.9 Debugging
The EFM8SB1 devices include an on-chip Silicon Labs 2-Wire (C2) debug interface to allow flash programming and in-system debug-
ging with the production part installed in the end application. The C2 interface uses a clock signal (C2CK) and a bi-directional C2 data
signal (C2D) to transfer information between the device and a host system. See the C2 Interface Specification for details on the C2
protocol.
EFM8SB1 Data Sheet
System Overview
silabs.com | Building a more connected world. Rev. 1.4 | 10
3.10 Bootloader
All devices come pre-programmed with a UART bootloader. This bootloader resides in the last page of flash and can be erased if it is
not needed.
The byte before the Lock Byte is the Bootloader Signature Byte. Setting this byte to a value of 0xA5 indicates the presence of the boot-
loader in the system. Any other value in this location indicates that the bootloader is not present in flash.
When a bootloader is present, the device will jump to the bootloader vector after any reset, allowing the bootloader to run. The boot-
loader then determines if the device should stay in bootload mode or jump to the reset vector located at 0x0000. When the bootloader
is not present, the device will jump to the reset vector of 0x0000 after any reset.
More information about the bootloader protocol and usage can be found in AN945: EFM8 Factory Bootloader User Guide. Application
notes can be found on the Silicon Labs website (www.silabs.com/8bit-appnotes) or within Simplicity Studio by using the [Application
Notes] tile.
8 KB Flash
(16 x 512 Byte pages)
Security Page
512 Bytes
0x1E00
0x1FFE
0x1FFF Lock Byte
Reserved
0xFFFF
0x2000
0x0000
0x1FFD
Bootloader Signature Byte
Bootloader
Bootloader Vector
Reset Vector
Figure 3.2. Flash Memory Map with Bootloader—8 kB Devices
Table 3.2. Summary of Pins for Bootloader Communication
Bootloader Pins for Bootload Communication
UART TX – P0.4
RX – P0.5
EFM8SB1 Data Sheet
System Overview
silabs.com | Building a more connected world. Rev. 1.4 | 11
Table 3.3. Summary of Pins for Bootload Mode Entry
Device Package Pin for Bootload Mode Entry
QFN20 P2.7 / C2D
QFN24 P2.7 / C2D
QSOP24 P2.7 / C2D
CSP16 P2.7 / C2D
EFM8SB1 Data Sheet
System Overview
silabs.com | Building a more connected world. Rev. 1.4 | 12
4. Electrical Specifications
4.1 Electrical Characteristics
All electrical parameters in all tables are specified under the conditions listed in Table 4.1 Recommended Operating Conditions on page
13, unless stated otherwise.
4.1.1 Recommended Operating Conditions
Table 4.1. Recommended Operating Conditions
Parameter Symbol Test Condition Min Typ Max Unit
Operating Supply Voltage on VDD VDD 1.8 2.4 3.6 V
Minimum RAM Data Retention
Voltage on VDD1
VRAM Not in Sleep Mode — 1.4 — V
Sleep Mode — 0.3 0.5 V
System Clock Frequency fSYSCLK 0 — 25 MHz
Operating Ambient Temperature TA–40 — 85 °C
Note:
1. All voltages with respect to GND.
EFM8SB1 Data Sheet
Electrical Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 13
4.1.2 Power Consumption
Table 4.2. Power Consumption
Parameter Symbol Conditions Min Typ Max Units
Digital Supply Current
Normal Mode supply current - Full
speed with code executing from
flash 3 , 4 , 5
IDD VDD = 1.8–3.6 V, fSYSCLK
= 24.5 MHz
— 3.6 4.5 mA
VDD = 1.8–3.6 V, fSYSCLK = 20
MHz
— 3.1 — mA
VDD = 1.8–3.6 V, fSYSCLK = 32.768
kHz
— 84 — µA
Normal Mode supply current fre-
quency sensitivity1, 3, 5
IDDFREQ VDD = 1.8–3.6 V, T = 25 °C,
fSYSCLK < 14 MHz
— 174 — µA/MHz
VDD = 1.8–3.6 V, T = 25 °C,
fSYSCLK > 14 MHz
— 88 — µA/MHz
Idle Mode supply current - Core
halted with peripherals running4 , 6
IDD VDD = 1.8–3.6 V, fSYSCLK = 24.5
MHz
— 1.8 3.0 mA
VDD = 1.8–3.6 V, fSYSCLK = 20
MHz
— 1.4 — mA
VDD = 1.8–3.6 V, fSYSCLK = 32.768
kHz
— 82 — µA
Idle Mode Supply Current Frequen-
cy Sensitivity1 ,6
IDDFREQ VDD = 1.8–3.6 V, T = 25 °C — 67 — µA/MHz
Suspend Mode Supply Current IDD VDD = 1.8–3.6 V — 77 — µA
Sleep Mode Supply Current with
RTC running from 32.768 kHz
crystal
IDD 1.8 V, T = 25 °C — 0.60 — µA
3.6 V, T = 25 °C — 0.80 — µA
1.8 V, T = 85 °C — 0.80 — µA
3.6 V, T = 85 °C — 1.00 — µA
Sleep Mode Supply Current with
RTC running from internal LFO
IDD 1.8 V, T = 25 °C — 0.30 — µA
3.6 V, T = 25 °C — 0.50 — µA
1.8 V, T = 85 °C — 0.50 — µA
3.6 V, T = 85 °C — 0.80 — µA
Sleep Mode Supply Current (RTC
off)
IDD 1.8 V, T = 25 °C — 0.05 — µA
3.6 V, T = 25 °C — 0.08 — µA
1.8 V, T = 85 °C — 0.20 — µA
3.6 V, T = 85 °C — 0.28 — µA
VDD Monitor Supply Current IVMON — 7 — µA
Oscillator Supply Current IHFOSC0 25 °C — 300 — µA
EFM8SB1 Data Sheet
Electrical Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 14
Parameter Symbol Conditions Min Typ Max Units
ADC0 Always-on Power Supply
Current7
IADC 300 ksps, 10-bit conversions or
75 ksps, 12-bit conversions
Normal bias settings
VDD = 3.0 V
— 740 — µA
150 ksps, 10-bit conversions or
37.5 ksps 12-bit conversions
Low power bias settings
VDD = 3.0 V
— 400 — µA
Comparator 0 (CMP0) Supply Cur-
rent
ICMP CPMD = 11 — 0.4 — µA
CPMD = 10 — 2.6 — µA
CPMD = 01 — 8.8 — µA
CPMD = 00 — 23 — µA
Internal Fast-Settling 1.65V ADC0
Reference, Always-on8
IVREFFS Normal Power Mode — 260 — µA
Low Power Mode — 140 — µA
Temp sensor Supply Current ITSENSE — 35 — µA
Capacitive Sense Module (CS0)
Supply Current
ICS0 CS module bias current, 25 °C — 50 60 µA
CS module alone, maximum code
output, 25 °C
— 90 125 µA
Wake-on-CS threshold (suspend
mode with regulator and CS mod-
ule on)9
— 130 180 µA
Programmable Current Reference
(IREF0) Supply Current10
IIREF0 Current Source, Either Power
Mode, Any Output Code
— 10 — µA
Low Power Mode, Current Sink
IREF0DAT = 000001
— 1 — µA
Low Power Mode, Current Sink
IREF0DAT = 111111
— 11 — µA
High Current Mode, Current Sink
IREF0DAT = 000001
— 12 — µA
High Current Mode, Current Sink
IREF0DAT = 111111
— 81 — µA
EFM8SB1 Data Sheet
Electrical Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 15
Parameter Symbol Conditions Min Typ Max Units
Note:
1. Based on device characterization data; Not production tested.
2. SYSCLK must be at least 32 kHz to enable debugging.
3. Digital Supply Current depends upon the particular code being executed. The values in this table are obtained with the CPU exe-
cuting an “sjmp $” loop, which is the compiled form of a while(1) loop in C. One iteration requires 3 CPU clock cycles, and the
flash memory is read on each cycle. The supply current will vary slightly based on the physical location of the sjmp instruction and
the number of flash address lines that toggle as a result. In the worst case, current can increase by up to 30% if the sjmp loop
straddles a 64-byte flash address boundary (e.g., 0x007F to 0x0080). Real-world code with larger loops and longer linear sequen-
ces will have few transitions across the 64-byte address boundaries.
4. Includes supply current from regulator and oscillator source (24.5 MHz high-frequency oscillator, 20 MHz low-power oscillator, 1
MHz external oscillator, or 32.768 kHz RTC oscillator).
5. IDD can be estimated for frequencies < 14 MHz by simply multiplying the frequency of interest by the frequency sensitivity num-
ber for that range, then adding an offset of 84 µA. When using these numbers to estimate IDD for > 14 MHz, the estimate should
be the current at 25 MHz minus the difference in current indicated by the frequency sensitivity number. For example: VDD = 3.0 V;
F = 20 MHz, IDD = 3.6 mA – (25 MHz – 20 MHz) x 0.088 mA/MHz = 3.16 mA assuming the same oscillator setting.
6. Idle IDD can be estimated by taking the current at 25 MHz minus the difference in current indicated by the frequency sensitivity
number. For example: VDD = 3.0 V; F = 5 MHz, Idle IDD = 1.75 mA – (25 MHz – 5 MHz) x 0.067 mA/MHz = 0.41 mA.
7. ADC0 always-on power excludes internal reference supply current.
8. The internal reference is enabled as-needed when operating the ADC in burst mode to save power.
9. Includes only current from regulator, CS module, and MCU in suspend mode.
10. IREF0 supply current only. Does not include current sourced or sunk from IREF0 output pin.
4.1.3 Reset and Supply Monitor
Table 4.3. Reset and Supply Monitor
Parameter Symbol Test Condition Min Typ Max Unit
VDD Supply Monitor Threshold VVDDM Reset Trigger 1.7 1.75 1.8 V
VWARN Early Warning 1.8 1.85 1.9 V
VDD Supply Monitor Turn-On Time tMON — 300 — ns
Power-On Reset (POR) Monitor
Threshold
VPOR Rising Voltage on VDD — 1.75 — V
Falling Voltage on VDD 0.75 1.0 1.3 V
VDD Ramp Time tRMP Time to VDD ≥ 1.8 V — — 3 ms
Reset Delay from non-POR source tRST Time between release of reset
source and code execution
— 10 — µs
Reset Delay from POR tPOR Relative to VDD > VPOR 3 10 31 ms
RST Low Time to Generate Reset tRSTL 15 — — µs
Missing Clock Detector Response
Time (final rising edge to reset)
tMCD FSYSCLK > 1 MHz 100 650 1000 µs
Missing Clock Detector Trigger
Frequency
FMCD — 7 10 kHz
EFM8SB1 Data Sheet
Electrical Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 16
4.1.4 Flash Memory
Table 4.4. Flash Memory
Parameter Symbol Test Condition Min Typ Max Units
Write Time1tWRITE One Byte 57 64 71 µs
Erase Time1tERASE One Page 28 32 36 ms
Endurance (Write/Erase Cycles) NWE 20 k 100 k — Cycles
CRC Calculation Time tCRC One 256-Byte Block
SYSCLK = 24.5 MHz
— 21.5 — µs
Note:
1. Does not include sequencing time before and after the write/erase operation, which may be multiple SYSCLK cycles.
2. Data Retention Information is published in the Quarterly Quality and Reliability Report.
4.1.5 Power Management Timing
Table 4.5. Power Management Timing
Parameter Symbol Test Condition Min Typ Max Units
Idle Mode Wake-up Time tIDLEWK 2 — 3 SYSCLKs
Suspend Mode Wake-up Time tSUS-
PENDWK
CLKDIV = 0x00
Low Power or Precision Osc.
— 400 — ns
Sleep Mode Wake-up Time tSLEEPWK — 2 — µs
4.1.6 Internal Oscillators
Table 4.6. Internal Oscillators
Parameter Symbol Test Condition Min Typ Max Unit
High Frequency Oscillator 0 (24.5 MHz)
Oscillator Frequency fHFOSC0 Full Temperature and Supply
Range
24 24.5 25 MHz
Low Power Oscillator (20 MHz)
Oscillator Frequency fLPOSC Full Temperature and Supply
Range
18 20 22 MHz
Low Frequency Oscillator (16.4 kHz internal RTC oscillator)
Oscillator Frequency fLFOSC Full Temperature and Supply
Range
13.1 16.4 19.7 kHz
EFM8SB1 Data Sheet
Electrical Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 17
4.1.7 Crystal Oscillator
Table 4.7. Crystal Oscillator
Parameter Symbol Test Condition Min Typ Max Unit
Crystal Frequency fXTAL 0.02 — 25 MHz
Crystal Drive Current IXTAL XFCN = 0 — 0.5 — µA
XFCN = 1 — 1.5 — µA
XFCN = 2 — 4.8 — µA
XFCN = 3 — 14 — µA
XFCN = 4 — 40 — µA
XFCN = 5 — 120 — µA
XFCN = 6 — 550 — µA
XFCN = 7 — 2.6 — mA
4.1.8 External Clock Input
Table 4.8. External Clock Input
Parameter Symbol Test Condition Min Typ Max Unit
External Input CMOS Clock
Frequency (at EXTCLK pin)
fCMOS 0 — 25 MHz
External Input CMOS Clock High
Time
tCMOSH 18 — — ns
External Input CMOS Clock Low
Time
tCMOSL 18 — — ns
EFM8SB1 Data Sheet
Electrical Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 18
4.1.9 ADC
Table 4.9. ADC
Parameter Symbol Test Condition Min Typ Max Unit
Resolution Nbits 12 Bit Mode 12 Bits
10 Bit Mode 10 Bits
Throughput Rate fS12 Bit Mode — — 75 ksps
10 Bit Mode — — 300 ksps
Tracking Time tTRK Initial Acquisition 1.5 — — us
Subsequent Acquisitions (DC in-
put, burst mode)
1.1 — — us
Power-On Time tPWR 1.5 — — µs
SAR Clock Frequency fSAR High Speed Mode, — — 8.33 MHz
Low Power Mode — — 4.4 MHz
Conversion Time TCNV 10-Bit Conversion 13 — — Clocks
Sample/Hold Capacitor CSAR Gain = 1 — 16 — pF
Gain = 0.5 — 13 — pF
Input Pin Capacitance CIN — 20 — pF
Input Mux Impedance RMUX — 5 — kΩ
Voltage Reference Range VREF 1 — VDD V
Input Voltage Range1VIN Gain = 1 0 — VREF V
Gain = 0.5 0 — 2 x VREF V
Power Supply Rejection Ratio PSRRADC Internal High Speed VREF — 67 — dB
External VREF — 74 — dB
DC Performance
Integral Nonlinearity INL 12 Bit Mode — ±1 ±1.5 LSB
10 Bit Mode — ±0.5 ±1 LSB
Differential Nonlinearity (Guaran-
teed Monotonic)
DNL 12 Bit Mode — ±0.8 ±1 LSB
10 Bit Mode — ±0.5 ±1 LSB
Offset Error EOFF 12 Bit Mode, VREF = 1.65 V –3 0 3 LSB
10 Bit Mode, VREF = 1.65 V –2 0 2 LSB
Offset Temperature Coefficient TCOFF — 0.004 — LSB/°C
Slope Error EM12 Bit Mode — ±0.02 ±0.1 %
10 Bit Mode — ±0.06 ±0.24 %
Dynamic Performance 10 kHz Sine Wave Input 1dB below full scale, Max throughput
Signal-to-Noise SNR 12 Bit Mode 62 65 — dB
10 Bit Mode 54 58 — dB
EFM8SB1 Data Sheet
Electrical Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 19
Parameter Symbol Test Condition Min Typ Max Unit
Signal-to-Noise Plus Distortion SNDR 12 Bit Mode 62 65 — dB
10 Bit Mode 54 58 — dB
Total Harmonic Distortion (Up to
5th Harmonic)
THD 12 Bit Mode — -76 — dB
10 Bit Mode — -73 — dB
Spurious-Free Dynamic Range SFDR 12 Bit Mode — 82 — dB
10 Bit Mode — 75 — dB
Note:
1. Absolute input pin voltage is limited by the VDD supply.
2. INL and DNL specifications for 12-bit mode do not include the first or last four ADC codes.
3. The maximum code in 12-bit mode is 0xFFFC. The Full Scale Error is referenced from the maximum code.
4.1.10 Voltage Reference
Table 4.10. Voltage Reference
Parameter Symbol Test Condition Min Typ Max Unit
Internal Fast Settling Reference
Output Voltage VREFFS 1.62 1.65 1.68 V
Temperature Coefficient TCREFFS — 50 — ppm/°C
Turn-on Time tREFFS — — 1.5 µs
Power Supply Rejection PSRRREF
FS
— 400 — ppm/V
External Reference
Input Voltage VEXTREF 1 — VDD V
Input Current IEXTREF Sample Rate = 300 ksps; VREF =
3.0 V
— 5.25 — µA
EFM8SB1 Data Sheet
Electrical Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 20
4.1.11 Temperature Sensor
Table 4.11. Temperature Sensor
Parameter Symbol Test Condition Min Typ Max Unit
Offset VOFF TA = 0 °C — 940 — mV
Offset Error1EOFF TA = 0 °C — 18 — mV
Slope M — 3.40 — mV/°C
Slope Error1EM— 40 — µV/°C
Linearity — ±1 — °C
Turn-on Time tPWR — 1.8 — µs
Note:
1. Represents one standard deviation from the mean.
EFM8SB1 Data Sheet
Electrical Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 21
4.1.12 Comparators
Table 4.12. Comparators
Parameter Symbol Test Condition Min Typ Max Unit
Response Time, CPMD = 00
(Highest Speed)
tRESP0 +100 mV Differential — 120 — ns
–100 mV Differential — 110 — ns
Response Time, CPMD = 11 (Low-
est Power)
tRESP3 +100 mV Differential — 1.25 — µs
–100 mV Differential — 3.2 — µs
Positive Hysterisis
Mode 0 (CPMD = 00)
HYSCP+ CPHYP = 00 — 0.4 — mV
CPHYP = 01 — 8 — mV
CPHYP = 10 — 16 — mV
CPHYP = 11 — 32 — mV
Negative Hysterisis
Mode 0 (CPMD = 00)
HYSCP- CPHYN = 00 — -0.4 — mV
CPHYN = 01 — –8 — mV
CPHYN = 10 — –16 — mV
CPHYN = 11 — –32 — mV
Positive Hysterisis
Mode 1 (CPMD = 01)
HYSCP+ CPHYP = 00 — 0.5 — mV
CPHYP = 01 — 6 — mV
CPHYP = 10 — 12 — mV
CPHYP = 11 — 24 — mV
Negative Hysterisis
Mode 1 (CPMD = 01)
HYSCP- CPHYN = 00 — -0.5 — mV
CPHYN = 01 — –6 — mV
CPHYN = 10 — –12 — mV
CPHYN = 11 — –24 — mV
Positive Hysterisis
Mode 2 (CPMD = 10)
HYSCP+ CPHYP = 00 — 0.7 — mV
CPHYP = 01 — 4.5 — mV
CPHYP = 10 — 9 — mV
CPHYP = 11 — 18 — mV
Negative Hysterisis
Mode 2 (CPMD = 10)
HYSCP- CPHYN = 00 — -0.6 — mV
CPHYN = 01 — –4.5 — mV
CPHYN = 10 — –9 — mV
CPHYN = 11 — –18 — mV
Positive Hysteresis
Mode 3 (CPMD = 11)
HYSCP+ CPHYP = 00 — 1.5 — mV
CPHYP = 01 — 4 — mV
CPHYP = 10 — 8 — mV
CPHYP = 11 — 16 — mV
EFM8SB1 Data Sheet
Electrical Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 22
Parameter Symbol Test Condition Min Typ Max Unit
Negative Hysteresis
Mode 3 (CPMD = 11)
HYSCP- CPHYN = 00 — -1.5 — mV
CPHYN = 01 — –4 — mV
CPHYN = 10 — –8 — mV
CPHYN = 11 — –16 — mV
Input Range (CP+ or CP–) VIN -0.25 — VDD+0.25 V
Input Pin Capacitance CCP — 12 — pF
Common-Mode Rejection Ratio CMRRCP — 70 — dB
Power Supply Rejection Ratio PSRRCP — 72 — dB
Input Offset Voltage VOFF TA = 25 °C -10 0 10 mV
Input Offset Tempco TCOFF — 3.5 — µV/°C
4.1.13 Programmable Current Reference (IREF0)
Table 4.13. Programmable Current Reference (IREF0)
Parameter Symbol Conditions Min Typ Max Units
Static Performance
Resolution Nbits 6 bits
Output Compliance Range VIOUT Low Power Mode, Source 0 — VDD – 0.4 V
High Current Mode, Source 0 — VDD – 0.8 V
Low Power Mode, Sink 0.3 — VDD V
High Current Mode, Sink 0.8 — VDD V
Integral Nonlinearity INL — <±0.2 ±1.0 LSB
Differential Nonlinearity DNL — <±0.2 ±1.0 LSB
Offset Error EOFF — <±0.1 ±0.5 LSB
Full Scale Error EFS Low Power Mode, Source — — ±5 %
High Current Mode, Source — — ±6 %
Low Power Mode, Sink — — ±8 %
High Current Mode, Sink — — ±8 %
Absolute Current Error EABS Low Power Mode Sourcing 20 µA — <±1 ±3 %
Dynamic Performance
Output Settling Time to 1/2 LSB tSETTLE — 300 — ns
Startup Time tPWR — 1 — µs
Note:
1. The PCA block may be used to improve IREF0 resolution by PWMing the two LSBs.
EFM8SB1 Data Sheet
Electrical Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 23
4.1.14 Capacitive Sense (CS0)
Table 4.14. Capacitive Sense (CS0)
Parameter Symbol Conditions Min Typ Max Units
Single Conversion Time1tCNV 12-bit Mode 20 25 40 µs
13-bit Mode (default) 21 27 42.5 µs
14-bit Mode 23 29 45 µs
16-bit Mode 26 33 50 µs
Number of Channels NCHAN 24-pin Packages 14 Channels
20-pin Packages 13 Channels
16-pin Packages 12 Channels
Capacitance per Code CLSB Default Configuration, 16-bit codes — 1 — fF
Maximum External Capacitive
Load
CEXTMAX CS0CG = 111b (Default) — 45 — pF
CS0CG = 000b — 500 — pF
Maximum External Series Impe-
dance
REXTMAX CS0CG = 111b (Default) — 50 — kΩ
Note:
1. Conversion time is specified with the default configuration.
2. RMS Noise is equivalent to one standard deviation. Peak-to-peak noise encompasses ±3.3 standard deviations. The RMS noise
value is specified with the default configuration.
EFM8SB1 Data Sheet
Electrical Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 24
4.1.15 Port I/O
Table 4.15. Port I/O
Parameter Symbol Test Condition Min Typ Max Unit
Output High Voltage (High Drive)1VOH IOH = –3 mA VDD – 0.7 — — V
Output Low Voltage (High Drive)1VOL IOL = 8.5 mA — — 0.6 V
Output High Voltage (Low Drive)1VOH IOH = –1 mA VDD – 0.7 — — V
Output Low Voltage (Low Drive)1VOL IOL = 1.4 mA — — 0.6 V
Input High Voltage VIH VDD = 2.0 to 3.6 V VDD – 0.6 — — V
VDD = 1.8 to 2.0 V 0.7 x VDD — — V
Input Low Voltage VIL VDD = 2.0 to 3.6 V — — 0.6 V
VDD = 1.8 to 2.0 V — — 0.3 x VDD V
Weak Pull-Up Current IPU VDD = 1.8 V
VIN = 0 V
— –4 — µA
VDD = 3.6 V
VIN = 0 V
–35 –20 — µA
Input Leakage ILK Weak pullup disabled or pin in ana-
log mode
–1 — 1 µA
Note:
1. See Figure 4.3 Typical VOH Curves on page 29 and Figure 4.4 Typical VOL Curves on page 30 for more information.
EFM8SB1 Data Sheet
Electrical Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 25
4.1.16 SMBus
Table 4.16. SMBus Peripheral Timing Performance (Master Mode)
Parameter Symbol Test Condition Min Typ Max Unit
Standard Mode (100 kHz Class)
I2C Operating Frequency fI2C 0 — 702kHz
SMBus Operating Frequency fSMB 401—702kHz
Bus Free Time Between STOP and
START Conditions
tBUF 9.4 — — µs
Hold Time After (Repeated)
START Condition
tHD:STA 4.7 — — µs
Repeated START Condition Setup
Time
tSU:STA 9.4 — — µs
STOP Condition Setup Time tSU:STO 9.4 — — µs
Data Hold Time tHD:DAT 4893— — ns
Data Setup Time tSU:DAT 4483— — ns
Detect Clock Low Timeout tTIMEOUT 25 — — ms
Clock Low Period tLOW 4.7 — — µs
Clock High Period tHIGH 9.4 — 504µs
Fast Mode (400 kHz Class)
I2C Operating Frequency fI2C 0 — 2552kHz
SMBus Operating Frequency fSMB 401—2552kHz
Bus Free Time Between STOP and
START Conditions
tBUF 2.6 — — µs
Hold Time After (Repeated)
START Condition
tHD:STA 1.3 — — µs
Repeated START Condition Setup
Time
tSU:STA 2.6 — — µs
STOP Condition Setup Time tSU:STO 2.6 — — µs
Data Hold Time tHD:DAT 4893— — ns
Data Setup Time tSU:DAT 4483— — ns
Detect Clock Low Timeout tTIMEOUT 25 — — ms
Clock Low Period tLOW 1.3 — — µs
Clock High Period tHIGH 2.6 — 504µs
EFM8SB1 Data Sheet
Electrical Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 26
Parameter Symbol Test Condition Min Typ Max Unit
Note:
1. The minimum SMBus frequency is limited by the maximum Clock High Period requirement of the SMBus specification.
2. The maximum I2C and SMBus frequencies are limited by the minimum Clock Low Period requirements of their respective specifi-
cations. The maximum frequency cannot be achieved with all combinations of oscillators and dividers available, but the effective
frequency must not exceed 256 kHz.
3. Data setup and hold timing at 25 MHz or lower with EXTHOLD set to 1.
4. SMBus has a maximum requirement of 50 µs for Clock High Period. Operating frequencies lower than 40 kHz will be longer than
50 µs. I2C can support periods longer than 50 µs.
Table 4.17. SMBus Peripheral Timing Formulas (Master Mode)
Parameter Symbol Clocks
SMBus Operating Frequency fSMB fCSO / 3
Bus Free Time Between STOP and START Conditions tBUF 2 / fCSO
Hold Time After (Repeated) START Condition tHD:STA 1 / fCSO
Repeated START Condition Setup Time tSU:STA 2 / fCSO
STOP Condition Setup Time tSU:STO 2 / fCSO
Clock Low Period tLOW 1 / fCSO
Clock High Period tHIGH 2 / fCSO
Note:
1. fCSO is the SMBus peripheral clock source overflow frequency.
tLOW
S PSP
VIH
VIL
VIH
VIL
SCL
SDA
tBUF
tHD:STA tHD:DAT
tHIGH
tSU:DAT
tSU:STA tSU:STO
Figure 4.1. SMBus Peripheral Timing Diagram (Master Mode)
EFM8SB1 Data Sheet
Electrical Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 27
4.2 Thermal Conditions
Table 4.18. Thermal Conditions
Parameter Symbol Test Condition Min Typ Max Unit
Thermal Resistance* θJA QFN-24 Packages — 35 — °C/W
QFN-20 Packages — 60 — °C/W
QSOP-24 Packages — 65 — °C/W
Note:
1. Thermal resistance assumes a multi-layer PCB with any exposed pad soldered to a PCB pad.
4.3 Absolute Maximum Ratings
Stresses above those listed in Table 4.19 Absolute Maximum Ratings on page 28 may cause permanent damage to the device. This
is a stress rating only and functional operation of the devices at those or any other conditions above those indicated in the operation
listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability. For
more information on the available quality and reliability data, see the Quality and Reliability Monitor Report at http://www.silabs.com/
support/quality/pages/default.aspx.
Table 4.19. Absolute Maximum Ratings
Parameter Symbol Test Condition Min Max Unit
Ambient Temperature Under Bias TBIAS –55 125 °C
Storage Temperature TSTG –65 150 °C
Voltage on VDD VDD GND–0.3 4.0 V
Voltage on I/O pins or RSTb VIN GND–0.3 VDD + 0.3 V
Total Current Sunk into Supply Pin IVDD — 400 mA
Total Current Sourced out of Ground
Pin
IGND 400 — mA
Current Sourced or Sunk by Any I/O
Pin or RSTb
IIO -100 100 mA
Maximum Total Current through all
Port Pins
IIOTOT — 200 mA
Operating Junction Temperature TJ–40 105 °C
Exposure to maximum rating conditions for extended periods may affect device reliability.
EFM8SB1 Data Sheet
Electrical Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 28
4.4 Typical Performance Curves
Figure 4.2. Typical Operating Supply Current (full supply voltage range)
Figure 4.3. Typical VOH Curves
EFM8SB1 Data Sheet
Electrical Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 29
Figure 4.4. Typical VOL Curves
EFM8SB1 Data Sheet
Electrical Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 30
5. Typical Connection Diagrams
5.1 Power
Figure 5.1 Power Connection Diagram on page 31 shows a typical connection diagram for the power pins of the EFM8SB1 devices.
EFM8SB1
Device
GND
1 µF and 0.1 µF bypass
capacitors required for
the power pins placed
as close to the pins as
possible.
1.8-3.6 V (in)
VDD
Figure 5.1. Power Connection Diagram
5.2 Debug
The diagram below shows a typical connection diagram for the debug connections pins. The pin sharing resistors are only required if
the functionality on the C2D (a GPIO pin) and the C2CK (RSTb) is routed to external circuitry. For example, if the RSTb pin is connec-
ted to an external switch with debouncing filter or if the GPIO sharing with the C2D pin is connected to an external circuit, the pin shar-
ing resistors and connections to the debug adapter must be placed on the hardware. Otherwise, these components and connections
can be omitted.
For more information on debug connections, see the example schematics and information available in AN127: "Pin Sharing Techniques
for the C2 Interface." Application notes can be found on the Silicon Labs website (http://www.silabs.com/8bit-appnotes) or in Simplicity
Studio.
EFM8SB1 Device External
System
(if pin sharing)
1 k 1 k
(if pin sharing)
C2CK
1 k 1 k
Debug Adapter
1 k
VDD
C2D
GND
Figure 5.2. Debug Connection Diagram
EFM8SB1 Data Sheet
Typical Connection Diagrams
silabs.com | Building a more connected world. Rev. 1.4 | 31
5.3 Other Connections
Other components or connections may be required to meet the system-level requirements. Application note, "AN203: 8-bit MCU Printed
Circuit Board Design Notes", contains detailed information on these connections. Application Notes can be accessed on the Silicon
Labs website (www.silabs.com/8bit-appnotes).
EFM8SB1 Data Sheet
Typical Connection Diagrams
silabs.com | Building a more connected world. Rev. 1.4 | 32
6. Pin Definitions
EFM8SB1 Data Sheet
Pin Definitions
silabs.com | Building a more connected world. Rev. 1.4 | 33
6.1 EFM8SB1x-QFN20 Pin Definitions
20
19
18
17
2
3
4
5
7
8
9
10
15
14
13
12
20 pin QFN
(Top View)
P0.1
P0.0
GND
VDD
RSTb / C2CK
P2.7 / C2D
P0.6
P0.7
P1.0
P1.1
GND
P1.2
P0.2
P0.3
P0.4
P0.5
GND
1
6 11
16
P1.7
P1.6
P1.5
P1.3
Figure 6.1. EFM8SB1x-QFN20 Pinout
Table 6.1. Pin Definitions for EFM8SB1x-QFN20
Pin
Number
Pin Name Description Crossbar Capability Additional Digital
Functions
Analog Functions
1 P0.1 Multifunction I/O Yes P0MAT.1
INT0.1
INT1.1
ADC0.1
CS0.1
AGND
2 P0.0 Multifunction I/O Yes P0MAT.0
INT0.0
INT1.0
CS0.0
VREF
3 GND Ground
4 VDD Supply Power Input
EFM8SB1 Data Sheet
Pin Definitions
silabs.com | Building a more connected world. Rev. 1.4 | 34
Pin
Number
Pin Name Description Crossbar Capability Additional Digital
Functions
Analog Functions
5 RSTb /
C2CK
Active-low Reset /
C2 Debug Clock
6 P2.7 /
C2D
Multifunction I/O /
C2 Debug Data
7 P1.7 Multifunction I/O Yes P1MAT.7 XTAL4
8 P1.6 Multifunction I/O Yes P1MAT.6 XTAL3
9 P1.5 Multifunction I/O Yes P1MAT.5 CS0.13
10 P1.3 Multifunction I/O Yes P1MAT.3 ADC0.11
CS0.11
11 P1.2 Multifunction I/O Yes P1MAT.2 ADC0.10
CS0.10
12 GND Ground
13 P1.1 Multifunction I/O Yes P1MAT.1 CMP0N.4
CS0.9
14 P1.0 Multifunction I/O Yes P1MAT.0 CMP0P.4
CS0.8
15 P0.7 Multifunction I/O Yes P0MAT.7
INT0.7
INT1.7
ADC0.7
CS0.7
IREF0
16 P0.6 Multifunction I/O Yes P0MAT.6
CNVSTR
INT0.6
INT1.6
ADC0.6
CS0.6
17 P0.5 Multifunction I/O Yes P0MAT.5
INT0.5
INT1.5
ADC0.5
CS0.5
18 P0.4 Multifunction I/O Yes P0MAT.4
INT0.4
INT1.4
ADC0.4
CS0.4
19 P0.3 Multifunction I/O Yes P0MAT.3
EXTCLK
WAKEOUT
INT0.3
INT1.3
ADC0.3
CS0.3
XTAL2
EFM8SB1 Data Sheet
Pin Definitions
silabs.com | Building a more connected world. Rev. 1.4 | 35
Pin
Number
Pin Name Description Crossbar Capability Additional Digital
Functions
Analog Functions
20 P0.2 Multifunction I/O Yes P0MAT.2
RTCOUT
INT0.2
INT1.2
ADC0.2
CS0.2
XTAL1
Center GND Ground
EFM8SB1 Data Sheet
Pin Definitions
silabs.com | Building a more connected world. Rev. 1.4 | 36
6.2 EFM8SB1x-QFN24 Pin Definitions
24
23
22
21
20
19
1
2
3
4
5
6
7
8
9
10
11
12
18
17
16
15
14
13
24 pin QFN
(Top View)
N/C
GND
VDD
N/C
N/C
RSTb / C2CK
P2.7 / C2D
P1.7
P1.6
N/C
P1.5
P1.4
P0.6
P0.7
P1.0
P1.1
P1.2
P1.3
P0.0
P0.1
P0.2
P0.3
P0.4
P0.5
VSS
Figure 6.2. EFM8SB1x-QFN24 Pinout
Table 6.2. Pin Definitions for EFM8SB1x-QFN24
Pin
Number
Pin Name Description Crossbar Capability Additional Digital
Functions
Analog Functions
1 N/C No Connection
2 GND Ground
3 VDD Supply Power Input
4 N/C No Connection
5 N/C No Connection
EFM8SB1 Data Sheet
Pin Definitions
silabs.com | Building a more connected world. Rev. 1.4 | 37
Pin
Number
Pin Name Description Crossbar Capability Additional Digital
Functions
Analog Functions
6 RSTb /
C2CK
Active-low Reset /
C2 Debug Clock
7 P2.7 /
C2D
Multifunction I/O /
C2 Debug Data
8 P1.7 Multifunction I/O Yes P1MAT.7 XTAL4
9 P1.6 Multifunction I/O Yes P1MAT.6 XTAL3
10 N/C No Connection
11 P1.5 Multifunction I/O Yes P1MAT.5 CS0.13
12 P1.4 Multifunction I/O Yes P1MAT.4 ADC0.12
CS0.12
13 P1.3 Multifunction I/O Yes P1MAT.3 ADC0.11
CS0.11
14 P1.2 Multifunction I/O Yes P1MAT.2 ADC0.10
CS0.10
15 P1.1 Multifunction I/O Yes P1MAT.1 CMP0N.4
CS0.9
16 P1.0 Multifunction I/O Yes P1MAT.0 CMP0P.4
CS0.8
17 P0.7 Multifunction I/O Yes P0MAT.7
INT0.7
INT1.7
ADC0.7
CS0.7
IREF0
18 P0.6 Multifunction I/O Yes P0MAT.6
CNVSTR
INT0.6
INT1.6
ADC0.6
CS0.6
19 P0.5 Multifunction I/O Yes P0MAT.5
INT0.5
INT1.5
ADC0.5
CS0.5
20 P0.4 Multifunction I/O Yes P0MAT.4
INT0.4
INT1.4
ADC0.4
CS0.4
21 P0.3 Multifunction I/O Yes P0MAT.3
EXTCLK
WAKEOUT
INT0.3
INT1.3
ADC0.3
CS0.3
XTAL2
EFM8SB1 Data Sheet
Pin Definitions
silabs.com | Building a more connected world. Rev. 1.4 | 38
Pin
Number
Pin Name Description Crossbar Capability Additional Digital
Functions
Analog Functions
22 P0.2 Multifunction I/O Yes P0MAT.2
RTCOUT
INT0.2
INT1.2
ADC0.2
CS0.2
XTAL1
23 P0.1 Multifunction I/O Yes P0MAT.1
INT0.1
INT1.1
ADC0.1
CS0.1
AGND
24 P0.0 Multifunction I/O Yes P0MAT.0
INT0.0
INT1.0
CS0.0
VREF
Center GND Ground
EFM8SB1 Data Sheet
Pin Definitions
silabs.com | Building a more connected world. Rev. 1.4 | 39
6.3 EFM8SB1x-QSOP24 Pin Definitions
P0.2
P0.1
P0.0
GND
VDD
RSTb / C2CK
C2D / P2.7
N/C
P0.4
P0.5
P0.6
P0.7
P1.0
P1.1
P1.2
P1.3
P1.4
2
1
4
3
5
6
7
24 pin QSOP
(Top View)
8
9
10
11
12
23
24
21
22
20
19
18
17
16
15
14
13
P1.6
P1.7
P0.3
N/C
N/C
N/C
P1.5
Figure 6.3. EFM8SB1x-QSOP24 Pinout
Table 6.3. Pin Definitions for EFM8SB1x-QSOP24
Pin
Number
Pin Name Description Crossbar Capability Additional Digital
Functions
Analog Functions
1 P0.2 Multifunction I/O Yes P0MAT.2
RTCOUT
INT0.2
INT1.2
ADC0.2
CS0.2
XTAL1
2 P0.1 Multifunction I/O Yes P0MAT.1
INT0.1
INT1.1
ADC0.1
CS0.1
AGND
EFM8SB1 Data Sheet
Pin Definitions
silabs.com | Building a more connected world. Rev. 1.4 | 40
Pin
Number
Pin Name Description Crossbar Capability Additional Digital
Functions
Analog Functions
3 P0.0 Multifunction I/O Yes P0MAT.0
INT0.0
INT1.0
CS0.0
VREF
4 N/C No Connection
5 GND Ground
6 VDD Supply Power Input
7 N/C No Connection
8 N/C No Connection
9 RSTb /
C2CK
Active-low Reset /
C2 Debug Clock
10 P2.7 /
C2D
Multifunction I/O /
C2 Debug Data
11 P1.7 Multifunction I/O Yes P1MAT.7 XTAL4
12 P1.6 Multifunction I/O Yes P1MAT.6 XTAL3
13 N/C No Connection
14 P1.5 Multifunction I/O Yes P1MAT.5 CS0.13
15 P1.4 Multifunction I/O Yes P1MAT.4 ADC0.12
CS0.12
16 P1.3 Multifunction I/O Yes P1MAT.3 ADC0.11
CS0.11
17 P1.2 Multifunction I/O Yes P1MAT.2 ADC0.10
CS0.10
18 P1.1 Multifunction I/O Yes P1MAT.1 CMP0N.4
CS0.9
19 P1.0 Multifunction I/O Yes P1MAT.0 CMP0P.4
CS0.8
20 P0.7 Multifunction I/O Yes P0MAT.7
INT0.7
INT1.7
ADC0.7
CS0.7
IREF0
21 P0.6 Multifunction I/O Yes P0MAT.6
CNVSTR
INT0.6
INT1.6
ADC0.6
CS0.6
22 P0.5 Multifunction I/O Yes P0MAT.5
INT0.5
INT1.5
ADC0.5
CS0.5
EFM8SB1 Data Sheet
Pin Definitions
silabs.com | Building a more connected world. Rev. 1.4 | 41
Pin
Number
Pin Name Description Crossbar Capability Additional Digital
Functions
Analog Functions
23 P0.4 Multifunction I/O Yes P0MAT.4
INT0.4
INT1.4
ADC0.4
CS0.4
24 P0.3 Multifunction I/O Yes P0MAT.3
EXTCLK
WAKEOUT
INT0.3
INT1.3
ADC0.3
CS0.3
XTAL2
EFM8SB1 Data Sheet
Pin Definitions
silabs.com | Building a more connected world. Rev. 1.4 | 42
6.4 EFM8SB1x-CSP16 Pin Definitions
CSP devices can be handled and soldered using industry standard surface mount assembly techniques. However, because CSP devi-
ces are essentially a piece of silicon and are not encapsulated in plastic, they are susceptible to mechanical damage and may be sensi-
tive to light. When CSP packages must be used in an environment exposed to light, it may be necessary to cover the top and sides with
an opaque material.
16 pin CSP
(Top View)
RSTb / C2CK P2.7 / C2D
A3
B3
C3
D3
P0.1
P0.2
P0.4
A2
B2
C2
D2
P1.4
P0.6
P0.3
P0.5
A1
B1
C1
D1
P1.1
P1.3
P1.0
P0.7
A4
B4
C4
D4
VDD
GND
P0.0
Figure 6.4. EFM8SB1x-CSP16 Pinout
Table 6.4. Pin Definitions for EFM8SB1x-CSP16
Pin
Number
Pin Name Description Crossbar Capability Additional Digital
Functions
Analog Functions
A1 P0.7 Multifunction I/O Yes P0MAT.7
INT0.7
INT1.7
ADC0.7
CS0.7
IREF0
A2 P0.5 Multifunction I/O Yes P0MAT.5
INT0.5
INT1.5
ADC0.5
CS0.5
A3 P0.4 Multifunction I/O Yes P0MAT.4
INT0.4
INT1.4
ADC0.4
CS0.4
EFM8SB1 Data Sheet
Pin Definitions
silabs.com | Building a more connected world. Rev. 1.4 | 43
Pin
Number
Pin Name Description Crossbar Capability Additional Digital
Functions
Analog Functions
A4 P0.0 Multifunction I/O Yes P0MAT.0
INT0.0
INT1.0
CS0.0
VREF
B1 P1.0 Multifunction I/O Yes P1MAT.0 CMP0P.4
CS0.8
B2 P0.3 Multifunction I/O Yes P0MAT.3
EXTCLK
WAKEOUT
INT0.3
INT1.3
ADC0.3
CS0.3
XTAL2
B3 P0.2 Multifunction I/O Yes P0MAT.2
RTCOUT
INT0.2
INT1.2
ADC0.2
CS0.2
XTAL1
B4 GND Ground
C1 P1.3 Multifunction I/O Yes P1MAT.3 ADC0.11
CS0.11
C2 P0.6 Multifunction I/O Yes P0MAT.6
CNVSTR
INT0.6
INT1.6
ADC0.6
CS0.6
C3 P0.1 Multifunction I/O Yes P0MAT.1
INT0.1
INT1.1
ADC0.1
CS0.1
AGND
C4 VDD Supply Power Input
D1 P1.1 Multifunction I/O Yes P1MAT.1 CMP0N.4
CS0.9
D2 P1.4 Multifunction I/O Yes P1MAT.4 ADC0.12
CS0.12
D3 RSTb /
C2CK
Active-low Reset /
C2 Debug Clock
D4 P2.7 /
C2D
Multifunction I/O /
C2 Debug Data
EFM8SB1 Data Sheet
Pin Definitions
silabs.com | Building a more connected world. Rev. 1.4 | 44
7. CSP16 Package Specifications
7.1 CSP16 Package Dimensions
Note: CSP devices can be handled and soldered using industry standard surface mount assembly techniques. However, because CSP
devices are essentially a piece of silicon and are not encapsulated in plastic, they are susceptible to mechanical damage and may be
sensitive to light. When CSP packages must be used in an environment exposed to light, it may be necessary to cover the top and
sides with an opaque material.
Figure 7.1. CSP16 Package Drawing
Table 7.1. CSP16 Package Dimensions
Dimension Min Typ Max
A 0.491 0.55 0.609
A1 0.17 — 0.23
A2 0.036 0.040 0.044
b 0.23 — 0.29
S 0.3075 0.31 0.3125
D 1.781 BSC
E 1.659 BSC
e 0.40 BSC
D1 1.20 BSC
EFM8SB1 Data Sheet
CSP16 Package Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 45
Dimension Min Typ Max
E1 1.20 BSC
SD 0.2
SE 0.2
n 16
aaa 0.03
bbb 0.06
ccc 0.05
ddd 0.015
Note:
1. All dimensions shown are in millimeters (mm) unless otherwise noted.
2. Dimensioning and Tolerancing per ANSI Y14.5M-1994.
3. Primary datum “C” and seating plane are defined by the spherical crowns of the solder balls.
4. Dimension “b” is measured at the maximum solder bump diameter, parallel to primary datum “C”.
5. Recommended card reflow profile is per the JEDEC/IPC J-STD-020C specification for Small Body Components.
EFM8SB1 Data Sheet
CSP16 Package Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 46
7.2 CSP16 PCB Land Pattern
Figure 7.2. CSP16 PCB Land Pattern Drawing
Table 7.2. CSP16 PCB Land Pattern Dimensions
Dimension Min Max
X 0.20
C1 1.20
C2 1.20
E1 0.40
E2 0.40
Note:
1. All dimensions shown are in millimeters (mm) unless otherwise noted.
2. Dimensioning and Tolerancing is per the ANSI Y14.5M-1994 specification.
3. This Land Pattern Design is based on the IPC-7351 guidelines.
4. All metal pads are to be non-solder mask defined (NSMD). Clearance between the solder mask and the metal pad is to be 60 µm
minimum, all the way around the pad.
5. A stainless steel, laser-cut and electro-polished stencil with trapezoidal walls should be used to assure good solder paste release.
6. The stencil thickness should be 0.075 mm (3 mils).
7. A stencil of square aperture (0.22 x 0.22 mm) is recommended.
8. A No-Clean, Type-3 solder paste is recommended.
9. The recommended card reflow profile is per the JEDEC/IPC J-STD-020 specification for Small Body Components.
EFM8SB1 Data Sheet
CSP16 Package Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 47
7.3 CSP16 Package Marking
PPPP
TTTT
YYWW
Figure 7.3. CSP16 Package Marking
The package marking consists of:
• PPPP – The part number designation.
• TTTT – A trace or manufacturing code.
• YY – The last 2 digits of the assembly year.
• WW – The 2-digit workweek when the device was assembled.
EFM8SB1 Data Sheet
CSP16 Package Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 48
8. QFN20G Package Specifications
Note: This section includes packaging information for G-grade devices.
EFM8SB1 Data Sheet
QFN20G Package Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 49
8.1 QFN20 Package Dimensions
Figure 8.1. QFN20 Package Drawing
Table 8.1. QFN20 Package Dimensions
Dimension Min Typ Max
A 0.50 0.55 0.60
A1 0.00 — 0.05
b 0.20 0.25 0.30
b1 0.275 0.325 0.375
D 3.00 BSC
D2 1.6 1.70 1.80
e 0.50 BSC
e1 0.513 BSC
E 3.00 BSC
E2 1.60 1.70 1.80
L 0.35 0.40 0.45
L1 0.00 — 0.10
aaa — 0.10 —
EFM8SB1 Data Sheet
QFN20G Package Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 50
Dimension Min Typ Max
bbb — 0.10 —
ddd — 0.05 —
eee — — 0.08
Note:
1. All dimensions shown are in millimeters (mm) unless otherwise noted.
2. Dimensioning and Tolerancing per ANSI Y14.5M-1994.
3. This drawing is based upon JEDEC Solid State Product Outline MO-248 but includes custom features which are toleranced per
supplier designation.
4. Recommended card reflow profile is per the JEDEC/IPC J-STD-020 specification for Small Body Components.
EFM8SB1 Data Sheet
QFN20G Package Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 51
8.2 QFN20 PCB Land Pattern
Figure 8.2. QFN20 PCB Land Pattern Drawing
Table 8.2. QFN20 PCB Land Pattern Dimensions
Dimension Min Max
C1 2.70
C2 2.70
C3 2.53
C4 2.53
E 0.50 REF
X1 0.20 0.30
X2 0.24 0.34
X3 1.70 1.80
Y1 0.50 0.60
Y2 0.24 0.34
Y3 1.70 1.80
EFM8SB1 Data Sheet
QFN20G Package Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 52
Dimension Min Max
Note:
1. All dimensions shown are in millimeters (mm) unless otherwise noted.
2. Dimensioning and Tolerancing is per the ANSI Y14.5M-1994 specification.
3. This Land Pattern Design is based on the IPC-7351 guidelines.
4. All metal pads are to be non-solder mask defined (NSMD). Clearance between the solder mask and the metal pad is to be 60 µm
minimum, all the way around the pad.
5. A stainless steel, laser-cut and electro-polished stencil with trapezoidal walls should be used to assure good solder paste release.
6. The stencil thickness should be 0.125 mm (5 mils).
7. The ratio of stencil aperture to land pad size should be 1:1 for the perimeter pads.
8. A 2x2 array of 0.75 mm openings on a 0.95 mm pitch should be used for the center pad to assure proper paste volume.
9. A No-Clean, Type-3 solder paste is recommended.
10. The recommended card reflow profile is per the JEDEC/IPC J-STD-020 specification for Small Body Components.
8.3 QFN20 Package Marking
PPPP
PPPP
TTTTTT
YYWW #
Figure 8.3. QFN20 Package Marking
The package marking consists of:
• PPPPPPPP – The part number designation.
• TTTTTT – A trace or manufacturing code.
• YY – The last 2 digits of the assembly year.
• WW – The 2-digit workweek when the device was assembled.
• # – The device revision (A, B, etc.).
EFM8SB1 Data Sheet
QFN20G Package Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 53
9. QFN20A Package Specifications
Note: This section includes packaging information for A-grade devices.
EFM8SB1 Data Sheet
QFN20A Package Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 54
9.1 QFN20 Package Dimensions
Figure 9.1. QFN20 Package Drawing
Table 9.1. QFN20 Package Dimensions
Dimension Min Typ Max
A 0.70 0.75 0.80
A1 0.00 0.035 0.05
b 0.20 0.25 0.30
b1 0.25 0.30 0.35
D 3.00 BSC
D2 1.60 1.70 1.80
e 0.50 BSC
e1 0.513 BSC
E 3.00 BSC
E2 1.60 1.70 1.80
L 0.35 0.40 0.45
L1 0.00 — 0.10
aaa — 0.10 —
EFM8SB1 Data Sheet
QFN20A Package Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 55
Dimension Min Typ Max
bbb — 0.10 —
ddd — 0.05 —
eee — — 0.08
Note:
1. All dimensions shown are in millimeters (mm) unless otherwise noted.
2. Dimensioning and Tolerancing per ANSI Y14.5M-1994.
3. This drawing is based upon JEDEC Solid State Product Outline MO-248 but includes custom features which are toleranced per
supplier designation.
4. Recommended card reflow profile is per the JEDEC/IPC J-STD-020 specification for Small Body Components.
EFM8SB1 Data Sheet
QFN20A Package Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 56
9.2 QFN20 PCB Land Pattern
Figure 9.2. QFN20 PCB Land Pattern Drawing
Table 9.2. QFN20 PCB Land Pattern Dimensions
Dimension Min Max
C1 2.70
C2 2.70
C3 2.53
C4 2.53
E 0.50 REF
X1 0.20 0.30
X2 0.24 0.34
X3 1.70 1.80
Y1 0.50 0.60
Y2 0.24 0.34
Y3 1.70 1.80
EFM8SB1 Data Sheet
QFN20A Package Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 57
Dimension Min Max
Note:
1. All dimensions shown are in millimeters (mm) unless otherwise noted.
2. Dimensioning and Tolerancing is per the ANSI Y14.5M-1994 specification.
3. This Land Pattern Design is based on the IPC-7351 guidelines.
4. All metal pads are to be non-solder mask defined (NSMD). Clearance between the solder mask and the metal pad is to be 60 µm
minimum, all the way around the pad.
5. A stainless steel, laser-cut and electro-polished stencil with trapezoidal walls should be used to assure good solder paste release.
6. The stencil thickness should be 0.125 mm (5 mils).
7. The ratio of stencil aperture to land pad size should be 1:1 for the perimeter pads.
8. A 2x2 array of 0.75 mm openings on a 0.95 mm pitch should be used for the center pad to assure proper paste volume.
9. A No-Clean, Type-3 solder paste is recommended.
10. The recommended card reflow profile is per the JEDEC/IPC J-STD-020 specification for Small Body Components.
9.3 QFN20 Package Marking
PPPP
PPPP
TTTTTT
YYWW #
Figure 9.3. QFN20 Package Marking
The package marking consists of:
• PPPPPPPP – The part number designation.
• TTTTTT – A trace or manufacturing code.
• YY – The last 2 digits of the assembly year.
• WW – The 2-digit workweek when the device was assembled.
• # – The device revision (A, B, etc.).
EFM8SB1 Data Sheet
QFN20A Package Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 58
10. QFN24 Package Specifications
10.1 QFN24 Package Dimensions
Figure 10.1. QFN24 Package Drawing
Table 10.1. QFN24 Package Dimensions
Dimension Min Typ Max
A 0.70 0.75 0.80
A1 0.00 — 0.05
b 0.18 0.25 0.30
D 4.00 BSC
D2 2.35 2.45 2.55
e 0.50 BSC
E 4.00 BSC
E2 2.35 2.45 2.55
L 0.30 0.40 0.50
aaa — — 0.10
bbb — — 0.10
ccc — — 0.08
ddd — — 0.10
EFM8SB1 Data Sheet
QFN24 Package Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 59
Dimension Min Typ Max
Note:
1. All dimensions shown are in millimeters (mm) unless otherwise noted.
2. Dimensioning and Tolerancing per ANSI Y14.5M-1994.
3. This drawing conforms to JEDEC Solid State Outline MO-220.
4. Recommended card reflow profile is per the JEDEC/IPC J-STD-020C specification for Small Body Components.
EFM8SB1 Data Sheet
QFN24 Package Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 60
10.2 QFN24 PCB Land Pattern
Figure 10.2. QFN24 PCB Land Pattern Drawing
Table 10.2. QFN24 PCB Land Pattern Dimensions
Dimension Min Max
C1 3.90 4.00
C2 3.90 4.00
E 0.50 BSC
X1 0.20 0.30
X2 2.70 2.80
Y1 0.65 0.75
Y2 2.70 2.80
EFM8SB1 Data Sheet
QFN24 Package Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 61
Dimension Min Max
Note:
1. All dimensions shown are in millimeters (mm) unless otherwise noted.
2. This Land Pattern Design is based on the IPC-7351 guidelines.
3. All metal pads are to be non-solder mask defined (NSMD). Clearance between the solder mask and the metal pad is to be 60 µm
minimum, all the way around the pad.
4. A stainless steel, laser-cut and electro-polished stencil with trapezoidal walls should be used to assure good solder paste release.
5. The stencil thickness should be 0.125 mm (5 mils).
6. The ratio of stencil aperture to land pad size should be 1:1 for all perimeter pads.
7. A 2 x 2 array of 1.10 mm x 1.10 mm openings on 1.30 mm pitch should be used for the center ground pad.
8. A No-Clean, Type-3 solder paste is recommended.
9. The recommended card reflow profile is per the JEDEC/IPC J-STD-020 specification for Small Body Components.
10.3 QFN24 Package Marking
PPPPPPPP
TTTTTT
YYWW #
Figure 10.3. QFN24 Package Marking
The package marking consists of:
• PPPPPPPP – The part number designation.
• TTTTTT – A trace or manufacturing code.
• YY – The last 2 digits of the assembly year.
• WW – The 2-digit workweek when the device was assembled.
• # – The device revision (A, B, etc.).
EFM8SB1 Data Sheet
QFN24 Package Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 62
11. QSOP24 Package Specifications
11.1 QSOP24 Package Dimensions
Figure 11.1. QSOP24 Package Drawing
Table 11.1. QSOP24 Package Dimensions
Dimension Min Typ Max
A — — 1.75
A1 0.10 — 0.25
b 0.20 — 0.30
c 0.10 — 0.25
D 8.65 BSC
E 6.00 BSC
E1 3.90 BSC
e 0.635 BSC
EFM8SB1 Data Sheet
QSOP24 Package Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 63
Dimension Min Typ Max
L 0.40 — 1.27
theta 0º — 8º
aaa 0.20
bbb 0.18
ccc 0.10
ddd 0.10
Note:
1. All dimensions shown are in millimeters (mm) unless otherwise noted.
2. Dimensioning and Tolerancing per ANSI Y14.5M-1994.
3. This drawing conforms to JEDEC outline MO-137, variation AE.
4. Recommended card reflow profile is per the JEDEC/IPC J-STD-020 specification for Small Body Components.
EFM8SB1 Data Sheet
QSOP24 Package Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 64
11.2 QSOP24 PCB Land Pattern
Figure 11.2. QSOP24 PCB Land Pattern Drawing
Table 11.2. QSOP24 PCB Land Pattern Dimensions
Dimension Min Max
C 5.20 5.30
E 0.635 BSC
X 0.30 0.40
Y 1.50 1.60
Note:
1. All dimensions shown are in millimeters (mm) unless otherwise noted.
2. This land pattern design is based on the IPC-7351 guidelines.
3. All metal pads are to be non-solder mask defined (NSMD). Clearance between the solder mask and the metal pad is to be 60 µm
minimum, all the way around the pad.
4. A stainless steel, laser-cut and electro-polished stencil with trapezoidal walls should be used to assure good solder paste release.
5. The stencil thickness should be 0.125 mm (5 mils).
6. The ratio of stencil aperture to land pad size should be 1:1 for all perimeter pads.
7. A No-Clean, Type-3 solder paste is recommended.
8. The recommended card reflow profile is per the JEDEC/IPC J-STD-020 specification for Small Body Components.
EFM8SB1 Data Sheet
QSOP24 Package Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 65
11.3 QSOP24 Package Marking
PPPPPPPP #
TTTTTTYYWW
EFM8
Figure 11.3. QSOP24 Package Marking
The package marking consists of:
• PPPPPPPP – The part number designation.
• TTTTTT – A trace or manufacturing code.
• YY – The last 2 digits of the assembly year.
• WW – The 2-digit workweek when the device was assembled.
• # – The device revision (A, B, etc.).
EFM8SB1 Data Sheet
QSOP24 Package Specifications
silabs.com | Building a more connected world. Rev. 1.4 | 66
12. Revision History
12.1 Revision 1.4
February 24, 2017
Updated A-grade QFN20 packaging information. The G-grade QFN20 and A-grade QFN20 devices now have different packages. Also
fixed a typo in the X2 dimension for the QFN20G pacakge.
12.2 Revision 1.3
September 23, 2016
Added A-grade parts.
Added 5.2 Debug.
Added bootloader pinout information and a reference to AN945: EFM8 Factory Bootloader User Guide in 3.10 Bootloader.
Added specifications for 4.1.16 SMBus.
Added CRC Calculation Time to 4.1.4 Flash Memory.
Added a note linking to the Typical VOH and VOL Performance graphs in 4.1.15 Port I/O.
Added the tPOR and adjusted the VPOR falling specifications in 4.1.3 Reset and Supply Monitor.
Added a note to 3.1 Introduction referencing the Reference Manual.
Added a note to 3.2 Power to clarify that entering Sleep may disconnect the active debug session.
Specified that the UART has a 1-byte FIFO in 3.6 Communications and Other Digital Peripherals.
12.3 Revision 1.2
Added CSP16 package.
Updated the "C2D / P2.0" pin on the QSOP24 pinout diagram to "C2D / P2.7."
Added crystal oscillator drive current typical values to Table 4.7 Crystal Oscillator on page 18.
Corrected the number of capacitive sense channels for 24- and 20-pin packages in Table 4.14 Capacitive Sense (CS0) on page 24.
Corrected E dimension shown in Figure 8.2 QFN20 PCB Land Pattern Drawing on page 52.
Added more information to 3.10 Bootloader.
12.4 Revision 1.1
Initial release.
EFM8SB1 Data Sheet
Revision History
silabs.com | Building a more connected world. Rev. 1.4 | 67
Table of Contents
1. Feature List ................................1
2. Ordering Information ............................2
3. System Overview ..............................4
3.1 Introduction...............................4
3.2 Power ................................5
3.3 I/O..................................5
3.4 Clocking ................................6
3.5 Counters/Timers and PWM .........................6
3.6 Communications and Other Digital Peripherals ...................7
3.7 Analog ................................9
3.8 Reset Sources .............................10
3.9 Debugging ...............................10
3.10 Bootloader ..............................11
4. Electrical Specifications .......................... 13
4.1 Electrical Characteristics ..........................13
4.1.1 Recommended Operating Conditions .....................13
4.1.2 Power Consumption ...........................14
4.1.3 Reset and Supply Monitor .........................16
4.1.4 Flash Memory .............................17
4.1.5 Power Management Timing ........................17
4.1.6 Internal Oscillators............................17
4.1.7 Crystal Oscillator ............................18
4.1.8 External Clock Input ...........................18
4.1.9 ADC ................................19
4.1.10 Voltage Reference ...........................20
4.1.11 Temperature Sensor ..........................21
4.1.12 Comparators .............................22
4.1.13 Programmable Current Reference (IREF0) ...................23
4.1.14 Capacitive Sense (CS0) .........................24
4.1.15 Port I/O ...............................25
4.1.16 SMBus ...............................26
4.2 Thermal Conditions ............................28
4.3 Absolute Maximum Ratings .........................28
4.4 Typical Performance Curves .........................29
5. Typical Connection Diagrams ........................ 31
5.1 Power ................................31
5.2 Debug ................................31
5.3 Other Connections ............................32
Table of Contents 68
6. Pin Definitions .............................. 33
6.1 EFM8SB1x-QFN20 Pin Definitions .......................34
6.2 EFM8SB1x-QFN24 Pin Definitions .......................37
6.3 EFM8SB1x-QSOP24 Pin Definitions ......................40
6.4 EFM8SB1x-CSP16 Pin Definitions .......................43
7. CSP16 Package Specifications........................ 45
7.1 CSP16 Package Dimensions .........................45
7.2 CSP16 PCB Land Pattern ..........................47
7.3 CSP16 Package Marking ..........................48
8. QFN20G Package Specifications ....................... 49
8.1 QFN20 Package Dimensions ........................50
8.2 QFN20 PCB Land Pattern .........................52
8.3 QFN20 Package Marking ..........................53
9. QFN20A Package Specifications ....................... 54
9.1 QFN20 Package Dimensions ........................55
9.2 QFN20 PCB Land Pattern .........................57
9.3 QFN20 Package Marking ..........................58
10. QFN24 Package Specifications ....................... 59
10.1 QFN24 Package Dimensions ........................59
10.2 QFN24 PCB Land Pattern .........................61
10.3 QFN24 Package Marking .........................62
11. QSOP24 Package Specifications ...................... 63
11.1 QSOP24 Package Dimensions .......................63
11.2 QSOP24 PCB Land Pattern ........................65
11.3 QSOP24 Package Marking .........................66
12. Revision History............................. 67
12.1 Revision 1.4 ..............................67
12.2 Revision 1.3 ..............................67
12.3 Revision 1.2 ..............................67
12.4 Revision 1.1 ..............................67
Table of Contents .............................. 68
Table of Contents 69
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