EMC1001-AFZQ-TR - MICROCHIP

SMSC EMC1001 DATASHEET Revision 1.6 (01-29-07)

Datasheet

PRODUCT FEATURES

EMC1001

1.5°C SMBus

Temperature Sensor in

Miniature SOT-23

General Description

The EMC1001 is a tiny SMBus te mperature sensor with

±1.5°C accuracy and two interrupts. Packaged in a

SOT23-6, the EMC1001 provides an accurate , low-cost,

low-current, solution for critical temperature monitoring

in a PC or embedded applications.

The EMC1001 generates two separate interrupts with

programmable thermal trip points. The THERM output

operates as a thermostat with programmable threshold

and hysteresis. The ALERT output can be configured

as a maskable SMBus alert with programmable

window comparator limits, or as a second THERM

output. An efficient fan control system can be created

since this output may be used to control a fan.

A power down mode extends battery life in portable

applications.

Each part number may be configured to respond to one

of four separate SMBus addresses.

Features

Self Contained Internal Temperature Sensor

—0.25°C resolution

—±1.5°C Accuracy 40°C to 85°C

Small 6-lead SOT lead-free RoHS compliant

packages

SMBus address selected by external resistor

— Select 1 of 4 per package, 8 addresses available

Maskable Interrupt using ALERT

One-shot Command during standby

Low Power, 3.0V to 3.6V Supply

— 47uA at 0.0625 Conversions per Second (Typical)

— 4.8uA in Standby (Typical)

SMBus 2.0 Compliant interface

Programmable temperature conversion rate

Applications

Desktop and Notebook Computers

Thermostats

Smart batteries

Industrial/Automotive

Other Electronic Systems

Simplified Block Diagram

EMC1001

Internal

Temp Diode

Switching

Current

SMCLK

Digital Mux

Limit Comparat or

High Limit Registers

THERM Hysteresis Register

Low Limit Registers

THERM Limit Register

Address Pointer Register

Conversion Rate Register

Interrupt MaskingStatus Regist er

Configuration Register

SMBus Interface

Temperature

ALERT

SMDATA

10-bit

delta-sigma

ADC

THERM

Order Number(s):

EMC1001-AFZQ-TR for 6 pin, SOT 23 Lead-Free RoHS compliant package

(tape and reel)

EMC1001-1-AFZQ-TR for 6 pin, SOT 23 Lead-Free RoHS compliant package

(alternate addresses, tape and reel)

See Table 1.2, "SMBus Address Configuration Information," on page 3

Reel size is 8,000 pieces.

80 ARKAY DRIVE, HAUPPAUGE, NY 11788 (631) 435-6000, FAX (631) 273-3123

Circuit diagrams and other information relating to SMSC products are included as a means of illustrating typical applications. Consequently, complete informa tion sufficient for

construction purposes is not necessarily given. Although the information has been checked and is believed to be accurate, no responsibility is assumed fo r inaccuraci es. SMSC

reserves the right to make changes to specifications and product descriptions at any time without notice. Contact your local SMSC sales office to obtain the latest specificati ons

before placing your product order. The provision of this information does not convey to the purchaser of the described semiconductor devices any licenses under any patent

rights or other intellectual property rights of SMSC or others. All sales are expressly conditional on your agreement to the terms and conditions of the most recently dated

version of SMSC's standard Terms of Sale Agreement dated before the date of your order (the "Terms of Sale Agreement"). The product may contain design defects or errors

known as anomalies which may cause the product's functions to deviate from published specifications. Anomaly sheets are available upon request. SMSC products are not

designed, intended, authorized or warranted for use in any life support or other application where product failure could cause or contribute to personal injury or severe property

damage. Any and all such uses without prior written approval of an Officer of SMSC and further testing and/or modification will be fully at the risk of the customer. Copies of

this document or other SMSC literature, as well as the Terms of Sale Agreement, may be obtained by visiting SMSC’s website at http://www.smsc.com. SMSC is a registered

trademark of Standard Microsystems Corporation (“SMSC”). Product names and company names are the trademarks of their respective holders.

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1.5°C SMBus Temperature Sensor in Miniature SOT-23

Datasheet

Revision 1.6 (01-29-07) 2 SMSC EMC1001

DATASHEET

1.5°C SMBus Temperature Sensor in Miniature SOT-23

Datasheet

SMSC EMC1001 3 Revision 1.6 (01-29-07)

DATASHEET

Chapter 1 Pin Configuration

Figure 1.1 EMC1001 Pin Configuration

Note 1.1 This value must be greater than 1kΩ ±5% and less than or equal to 7.5kΩ ±5%.

Note 1.2 The pull-up resistor must be connected to VDD (pin 1), and the total capacitance on this

pin must be less than 100pF.

Table 1.1 Pin Description

PIN PIN NO. DESCRIPTION

ADDR/THERM 1 Logic output that can be u sed to turn on/off a fan or throttle a CPU clock

in the event of an over-temperature condition. This is an open-drain

output. This pin is sampled following power up and the value of the pull

up resistor determines the SMBus slave address per Table 1.2.Total

capacitance on this pin must not exceed 100 pF, and the pull-up resistor

must be connected to the same supply voltage as VDD

GND 2 Ground.

VDD 3 Supply Voltage, 3.0V to 3.6V.

SMCLK 4 SMBus clock input.

ALERT/THERM2 5 Logic output used as interrupt, SMBus alert or as a second THERM output.

This is an open-drain output.

SMDATA 6 SMBus data input/output, open drain output.

Tab le 1.2 SMBus Address Configuration Inform ation

PART NUMBER ADDR/THERM

PULL-UP RESISTOR SMBUS

ADDRESS PACKAGE

DESCRIPTION

EMC1001 7.5kΩ ±5% Note 1.1, Note 1.2 1001 000b 6-Lead SOT-23

12kΩ ±5% Note 1.2 1001 001b 6-Lead SOT-23

20kΩ ±5% Note 1.2 0111 000b 6-Lead SOT-23

33kΩ ±5% Note 1.2 0111 001b 6-Lead SOT-23

EMC1001-1 7.5kΩ ±5% Note 1.1, Note 1.2 1001 010b 6-Lead SOT-23

12kΩ ±5% Note 1.2 1001 011b 6-Lead SOT-23

20kΩ ±5% Note 1.2 0111 010b 6-Lead SOT-23

33kΩ ±5% Note 1.2 0111 011b 6-Lead SOT-23

GND

VDD

SMDATA

SMCLK

ADDR/THERM

ALERT/THERM2

1.5°C SMBus Temperature Sensor in Miniature SOT-23

Datasheet

Revision 1.6 (01-29-07) 4 SMSC EMC1001

DATASHEET

Note: Stresses above those listed could cause damage to the device. This is a stress rating only

and functional operation of the device at any other condition above those indicated in the

operation sections of this specification is not implied. When powering this device from

laboratory or system power supplies, it is important that the Absolute Maximum Ratings not be

exceeded or device failure can result. Some power supplies exhibit voltage spikes on their

outputs when the AC power is switched on or off. In addition, voltage transients on the AC

power line may appea r on the DC output. If this possibility exists, it is suggested that a clamp

circuit be used.

Table 1.3 Absolute Maximum Ratings

PARAMETER RATING UNIT

Supply Voltage VDD -0.3 to 5.0 V

Voltage on ALERT/THERM2, SMDATA and SMCLK pins -0.3 to 5.5 V

Voltage on any other pin -0.3 to VDD+0.3 V

Operating Temperature Range -25 to +125 °C

Storage Temperature Range -55 to +150 °C

Lead Temperature Range Refer to JEDEC

Spec. J-STD-020

Package Thermal Characteristics for SOT23-6

Power Dissipation TBD mW @ 70oC

Thermal Resistance 111.5 oC/W

ESD Rating, All Pins (Human Body Model) 2000 V

1.5°C SMBus Temperature Sensor in Miniature SOT-23

Datasheet

SMSC EMC1001 5 Revision 1.6 (01-29-07)

DATASHEET

Chapter 2 Electrical Characteristics

Table 2.1 Electrical Characteris tics

VDD=3.0V to 3.6V, TA= -25°C to +125°C, Typical values at TA = 27°C unless otherwise noted

PARAMETER SYMBOL MIN TYP MAX UNITS CONDITIONS

DC Power

Supply Voltage VDD 3.0 3.3 3.6 V

Average Operating Current IDD 47 TBD μA 0.0625 conversion/s

See Table 4.6,

"Conversion Rates,"

on page 14

IPD 4.8 10 μA Standby mode

Temperature Measurement

Accuracy ±0.5 ±1.5 °C40°C≤TA≤85°C

±1±3°C-25°C≤TA≤125°C

Resolution 0.25 °C

Conversion Time 26 ms

Voltage Tolerance

Voltage at pin (ADDR/THERM, )V

TOL -0.3 3.6 V

Voltage at pin (ALERT/THERM2,

SMDATA,SMCLK) VTOL -0.3 5.5 V

Digital Outputs (ADDR/THERM, ALERT/THERM2)

Output Low Voltage VOL 0.4 V IOUT=-4mA

High Level Leakage Current IOH 0.1 1 μAVOUT=VDD

SMBus Interface (SMDATA,SMCLK)

Input High Level VIH 2.0 V

Input Low Level VIL 0.8 V

Input High/Low Current IIH/IIL -1 1 μA

Hysteresis 500 mV

Input Capacitance 5 pF

Output Low Sink Current 6 mA SMDATA = 0.6V

SMBus Timing

Clock Frequency FSMB 10 400 kHz

Spike Suppression 50 ns

1.5°C SMBus Temperature Sensor in Miniature SOT-23

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Revision 1.6 (01-29-07) 6 SMSC EMC1001

DATASHEET

Note 2.1 300nS rise time max is required for 400kHz bus operation. For lower clock frequencies,

the maximum rise time is (0.1/FSMB)+50nS

Bus free time Start to Stop TBUF 1.3 μs

Hold time Start THD:STA 0.6 μs

Setup time Start TSU:STA 0.6 μs

Setup time Stop TSU:STO 0.6 μs

Data Hold Time THD:DAT 0.3 μs

Data Setup Time TSU:DAT 100 ns

Clock Low Period TLOW 1.3 μs

Clock High Period THIGH 0.6 μs

Clock/Data Fall Time TF* 300 ns *Min = 20+0.1Cb ns

Clock/Data Rise Time TR*300

Note

2.1

ns *Min = 20+0.1Cb ns

Capacitive Load (each bus line) Cb0.6 400 pF

Table 2.1 Electrical Characteristics (continued)

VDD=3.0V to 3.6V, TA= -25°C to +125°C, Typical values at TA = 27°C unless otherwise noted

PARAMETER SYMBOL MIN TYP MAX UNITS CONDITIONS

1.5°C SMBus Temperature Sensor in Miniature SOT-23

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SMSC EMC1001 7 Revision 1.6 (01-29-07)

DATASHEET

Chapter 3 System Management Bus Interface Protocol

A host controller, such as an SMSC I/O controller, communicates with the EMC1001 via the two wire

serial interface named SMBus. The SMBus interface is used to read and write registers in the

EMC1001, which is a slave-only device. A detailed timing diagram is shown in Figure 3.1.

Figure 3.1 System Management Bus Timing Diagram

The EMC1001 implements a subset of the SMBus specification and supports Write Byte, Read Byte,

Send Byte, Receive Byte, and Alert Response Address protocols. as shown. In the tables that describe

the protocol, the “gray” columns indicate that the slave is driving the bus.

3.1 Write Byte

The Write Byte protocol is used to write one byte of data to the registers as shown below:

3.2 Read Byte

The Read Byte protocol is used to read one byte of data from the registers as shown below:

3.3 Send Byte

The Send Byte protocol is used to set the Internal Address Register to the correct Address. The Send

Byte can be followed by the Receive Byte protocol described below in order to read data from the

the write byte protocol must b e use d as described in subsection above . The send byte protocol is sho wn

in Table 3.3.

Table 3.1 SMBus Write Byte Protocol

START SLAVE ADDRESS WR ACK COMMAND ACK DATA ACK STOP

171

181811

Table 3.2 SMBus Read Byte Protocol

START SLAVE ADDRESS WR ACK COMMAND ACK START SLAVE ADDRESS RD ACK DATA NACK STOP

1711811 7 1181 1

Table 3.3 SMBus Send Byte Protocol

FIELD: START SLAVE ADDR WR ACK REG. ADDR ACK STOP

Bits: 1711811

SMDATA

SMCLK

TLOW

THIGH

TBUF

THD:STA

PSS - Start C ondition P - Stop Condition

THD:DAT TSU:DAT TSU:STA

THD:STA

TSU:STO

1.5°C SMBus Temperature Sensor in Miniature SOT-23

Datasheet

Revision 1.6 (01-29-07) 8 SMSC EMC1001

DATASHEET

3.4 Receive Byte

The Receive Byte protocol is used to read data from a reg ister when the internal register addre ss pointer

is known to be at the right location (e.g. set via Send Byte). This can be used for consecutive reads of

the same register as shown below:

3.5 Alert Response Address

The ALERT/THERM2 output can be used as an SMBALERT# as described in 4.3, "ALERT/THERM2

Output," on page 11. The Alert Response Address is polled by the Host whenever it detects an

SMBALERT#, i.e. when the ALERT/THERM2 pin is asserted. The EMC1001 will acknowlege the Alert

Response Address and respond with its device address as shown below.

3.6 SMBus Addresses

The EMC1001 is available in two versions, each of which has four 7-bit slave addresses that are

enabled based on the pull-up resistor on the ADDR/THERM pin. The value of this pull up resistor

determines the slave address per Table 1.2 on page 3 . Attempting to communicate with the EMC1001

SMBus interface with an invali d slave address or invalid protocol results in no response from the device

and does not affect its register contents. The EMC1001 supports stretching of the SMCLK signal by

other devices on the SMBus but will not perform this operation itself. The EMC1001 has an SMBus

timeout feature. Bit 7 of the SMBus Timeout Enable register enables this function when set to 1 (the

default setting is 0). When this feature is enabled, the SMBus will timeout after approximately 25ms

of inactivity.

Table 3.4 SMBus Receive Byte Protocol

FIELD: START SLAVE ADDR RD ACK REG. DATA NACK STOP

Bits: 1711811

Table 3.5 Modified SMBus Receive Byte Protocol Response to ARA

FIELD: START

ALERT

RESPONSE

ADDRESS RD ACK EMC1001 SLAVE

ADDRESS NACK STOP

Bits: 1711 8 11

1.5°C SMBus Temperature Sensor in Miniature SOT-23

Datasheet

SMSC EMC1001 9 Revision 1.6 (01-29-07)

DATASHEET

Chapter 4 Product Description

The EMC1001 is an SMBus temperature that monitors a single temperature zone. Thermal

management is performed in cooperatio n with a ho st device. The host read s the tempera ture data from

the EMC1001 an d takes appropria te action such as controll ing fan speed or processor clock frequency.

The EMC1001 has programmable temper ature limit registers that define a safe operating window. After

the host has configured the temperature limits, the EMC1001 can operate as a free-running

independent watchdog to warn the host of temperature hot spots without requiring the host to poll the

device. The ADDR/THERM output can be used to control a fan without host intervention.

Figure 4.1 Controlling a fan without host intervention.

The EMC1001 has two basic modes of operation:

Run Mode: In this mode, the EMC1001 continuously converts temperature data and updates its

registers. The rate of temperature conversion is configured as shown in Section 4.9 on page 14.

Standby Mode: In this mode, the EMC1001 is placed in standby to conserve power as described

in Section 4.5 on page 12.

4.1 Temperature Monitors

Thermal diode temperature measu rements are based on the change in forward bias voltage (ΔVBE) of

a diode when operated at two different currents:

The change in ΔVBE voltage is proportional to absolute temperature T.

where:

k = Boltzmann’s constant

T = absolute temperature in Kelvin

q = electron charge

= diode ideality factor

ADDR/THERM

ALERT/THERM2

EMC1001 Host

Fan

Driver

SMDATA

Internal

Diode

SMCLK

SMBus

Interface

⎟

⎠

⎞

⎜

⎝

⎛

=−=Δ

LOW

HIGH

LOWBEHIGHBEBE I

VVV ln

1.5°C SMBus Temperature Sensor in Miniature SOT-23

Datasheet

Revision 1.6 (01-29-07) 10 SMSC EMC1001

DATASHEET

Figure 4.2 Detailed Block Diagram

Figure 4.2 shows a detailed block diagram of the temperature measurement circuit. The EMC1001

incorporates switched capacitor technology that integrates the temperature diode ΔVBE from different

bias currents. The negative terminal, DN, for the temperature diode is internally biased with a forward

diode voltage referenced to ground.

The advantages of this architecture over Nyquist rate FLASH or SAR converters are superb linearity

and inherent noise immunity. The linearity can be directly attributed to the delta-sigma ADC single-bit

comparator while the noise immunity is achieved by the ~20ms integration time which translates to

50Hz input noise bandwidth.

4.2 Temperature Measurement Results and Data

The 10-bit temperature measurement results are stored in temperature value registers. Table 4.1

shows the two’s complement temperature data format with an LSB equivalent to 0.25°C.

Note 4.1 Temperature measurement returns 1100 0000 00 for all temperatures ≤ -64.00°C

Note 4.2 Temperature measurement returns 0111 1111 11 for all temperatures ≥ +127.75°C

The eight most significant bi ts are stored in the Temperature Value High Byte re gister and the two lea st

significant bits stored in the Temperature Value Low Byte register as outlined in Table 4.2. The six LSB

positions of the Temperature Value Low Byte register always read zero. In Table 4.2, the upper case

Table 4.1 Temperature Data Format

TEMPERATURE

VALID RANGE

–40°C TO 125°C

TWO’S COMPLEMENT

-0.25°C 1111 1111 11 Note 4.1

0.0°C 0000 0000 00

+0.25°C 0000 0000 01

+0.50°C 0000 0000 10

+0.75°C 0000 0000 11

+1°C 0000 0001 00

+125°C 0 111 11 0 1 0 0 Note 4.2

Delta Vbe

Sample

Hold

Ibias

Ilow

Ihigh

1-bit

delta-sigma

Modulator

Digital

Averaging

Filter

VDD

Internal or

Remote Diode Bias

Diode

10-bit Output

1.5°C SMBus Temperature Sensor in Miniature SOT-23

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SMSC EMC1001 11 Revision 1.6 (01-29-07)

DATASHEET

“B” shows the bit positi on of a 16-bit word created by concat enating the High Byte and Low Byte, and

the lower case “b” shows the bit position in the 10-bit value.

4.3 ALERT/THERM2 Output

The ALERT/THERM2 output asserts if an out of limit measurement is detected (TA ≤ low limit or TA >

high limit). The ALERT/THERM2 pin is an open drain output and requires a pull up resistor to VDD.The

ALERT/THERM2 pin can be used as an SMBALERT#, or may be configured as a second THERM output.

As described in the SMBus specification, an SMBus slave may inform the SMBus master that it wants

to talk by asserting the SMBALERT# signal. One or more ALERT outputs can be hardwired together

as a wired-or bus to a common input.

The ALERT/THERM2 pin resets when the EMC1001 responds to an alert response addre ss (ARA=0001

100) sent by the host , and if the out of li mit condition no longer exi sts, but it does not reset if the error

condition remains. The ALERT/THERM2 pin can be masked so that it wi ll not assert in the event of an

out of limit temperature measurement, except when it is configured as a second THERM pin.

Figure 4.3 ALERT Response to Temperature Limits Exceeded

The ALERT/THERM2 pin can be configured as a se cond THERM pin that asserts when the temp erature

measurement exceeds the Temperature High Limit value. In this mode, the output will not de-assert

until the temerature drops below the Temperature High Limit minus the THERM Hysteresis value.

4.4 ADDR/THERM Output

The ADDR/THERM output asserts if the temperature meas urement exceeds the programmable THERM

limit. It can be used to drive a fan or other failsafe devices. The ADDR/THERM pin is open drain and

requires a pull up resistor to VDD. The value of this pull up resistor determines the slave address per

Table 1.2 on page 3. The ADDR/THERM pin cannot be masked.

When the ADDR/THERM pin is asserted, it will not de-assert until the temperature drops below the

THERM limit minus the THERM hysteresis value.

Table 4.2 Bit Position of Two Byte Values

HIGH BYTE LOW BYTE

B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0

b9 b8 b7 b6 b5 b4 b3 b2 b1 b0 0 0 0 0 0 0

Temp

Time

Temperature Hi gh Limit

Temperature Low Limit

ALERT/THERM2

Logic High

Logic

Level

SMBus ARA

1.5°C SMBus Temperature Sensor in Miniature SOT-23

Datasheet

Revision 1.6 (01-29-07) 12 SMSC EMC1001

DATASHEET

Figure 4.4 THERM Response to THERM Limit Exceeded

4.5 Standby Mode

The EMC1001 can be set to standby mode (low power) by setting a bit in the Configuration Register

as described in Section 4.8 on page 13. This shuts down al l i nt ernal an alog fun cti ons whil e t he SMBus

remains enabled. When the EMC1001 is in standby mode, a One-Shot command measurement can

be initiated. The user may also write new values to the limit registers described in Section 4.10 on

page 15 while in standby. If the previously stored temperature is outside any of the new limits, the

ALERT/THERM2 output will respond as described in Section 4.3 and the ADDR/THERM output will

respond as described in Section 4.4.

4.6 Register Allocation

The following registers shown in Table 4.3 are accessible through the SMBus:

Table 4.3 Register Map

ADDRESS

(HEX) R/W REGISTER NAME POWER-ON DEFAULT

00 R Temperature Value High Byte 0000 0000

01 R Status undefined

02 R Temperature Value Low Byte 0000 0000

03 R/W Configuration 0000 0000

04 R/W Conversion Rate 0000 0100

05 R/W Temperature High Limit High Byte 0101 0101 (85°C)

06 R/W Temperature High Limit Low Byte 0000 0000

07 R/W Temperature Low Limit High Byte 0000 0000 (0°C)

08 R/W Temperature Low Limit Low Byte 0000 0000

0F W One-Shot N/A

20 R/W THERM Limit 0101 0101 (85°C)

21 R/W THERM Hysteresis 0000 1010 (10°C)

22 R/W SMBus Timeout Enable 0000 0001

FD R Product ID Register 0000 0000 (EMC1001)

0000 0001 (EMC1001-1)

FE R Manufacture ID 0101 1101

FF R Revision Number 0000 0011 Note 4.3

Temp

Time

THERM Limit

THERM Limit - THERM Hysterisis

THERM

Hysteresis

Logic High

Logic

Level

1.5°C SMBus Temperature Sensor in Miniature SOT-23

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SMSC EMC1001 13 Revision 1.6 (01-29-07)

DATASHEET

Note 4.3 Revision number may change. Please obtain the latest version of this document from the

SMSC web site.

At device power-up, the default values are stored in all registers. A power-on-reset is initiated when

power is first applied to the part and the VDD supply exceeds the POR threshold. Reads of undefined

registers will return 00h and writes to undefined registers will be ignored.

The EMC1001 uses an interlock mechanism that locks the low byte value when the high byte register

is read. This prevents updates to the low byte register between high byte and low byte reads. This

interlock mechanism requires that the high byte register always be read prior to reading the low byte

4.7 Status Register

The status register is a read only register that stores the operational status of the part. When either

TLOW or THIGH are set (TA ≤ low limit or TA > high limit) and the ALERT/THERM2 pin is not masked,

the ALERT/THERM2 pin will assert. See Section 4.3 on page 11 for more details on the ALERT

function.

Bit 7 indicates that the ADC is busy converting a value. Bits 6 and 5 indicate that the temperature

measurement is above or below the li mits respectively. Bit 0 indica tes that the measured temperature

has exceeded the THERM limit. When bit 0 goes high the ADDR/THERM output will be asserted.

Each bit is cleared individually when the status register is read, provided that the error condition for

that bit no longer exi sts. The ALERT/THERM2 ou tput is latched a nd will not be reset until the host has

responded with an alert response address (ARA=0001 100). The ALERT/THERM2 out put will not reset

if the status register has not been cleared.

4.8 Configuration Register

The configuration register controls the functionality of the temperature measurements.

Table 4.4 Status Register

STATUS REGISTER

BIT NAME FUNCTION

7 Busy 1 when ADC is converting

6 THIGH 1 when Temperature High Limit is exceeded

5 TLOW 1 when Temperature Low Limit is exceeded

4Reserved

3Reserved

2Reserved

1Reserved

0 THRM 1 when THERM limit is exceeded

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Revision 1.6 (01-29-07) 14 SMSC EMC1001

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Bit 7 is used to mask the ALERT/THERM2 signal. When this bit is set to 0, any out of limit condition

will assert ALERT/THERM2. This bit i s ignored if th e ALERT/THERM2 pin is configured as THERM2 signal

by bit 5.

Bit 6 initiates ADC conversions. When this bit is low, the ADC will convert temperatures in a

continuous mode. When this bit is high, the ADC will be in standby mode, thus reducing supply

current significantly though the SMBus will still be active. If bit 6 is 1 and the one-shot register is

written to, the ADC will execute a temperature measurement and then return to standby mode.

Bit 5 sets the ALERT/THERM2 pin to act as either an SMBALERT# signal or as the THERM2 signal. If

bit 5 is set to 1 the ALERT/THERM2 pin acts as the THERM2 signal and bit 7 is ignored.

4.9 Conversion Rate Register

The conversion rate register determines how many times the temperature value will be updated per

second. The lowest 4 bits confi gure a programmable delay that waits between con secutive conversion

cycles to obtain the desired conversion rate. Table 4.6 shows the conversion rate and the associated

quiescent current.

Table 4.5 Configuration Register

CONFIGURATION REGISTER

BIT NAME FUNCTION DEFAULT

7 MASK1 0 = ALERT enabled

1 = ALERT disabled 0

6 RUN/STOP 0 = Active mode (continuously running)

1 = Standby mode 0

5ALERT or THERM2 0 = ALERT

1 = THERM2 0

4 – 0 Reserved 0

Table 4.6 Conve rsion Rates

CONVERSION RATE

VALUE CONVERSIONS/SECOND TYPICAL QUIESCENT CURRENT (μA)

00h 0.0625 36

01h 0.125 37

02h 0.25 38

03h 0.5 40

04h 1 44

05h 2 54

06h 4 71

07h 8 109

08h 16 182

09h 32 326

0Ah to FFh Reserved

1.5°C SMBus Temperature Sensor in Miniature SOT-23

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SMSC EMC1001 15 Revision 1.6 (01-29-07)

DATASHEET

4.10 Limit Registers

The user can configure high and low temperature limits and an independent THERM limit. The

temperature high limit (T H) is a 10-bit valu e that is set by the Temperature High Limit High Byte register

and the Temperature High Limit Low Byte register. The Temperature High Limit Low Byte register

contains the two least significant bits as shown in Table 4.2 on page 11. The two least significant bits

are stored in the upper two bits of the register, and the six LSB positions of this register always read

zero.

The temperature low limit (TL) is a 10-bit value that is set by the Temperature Low Limit High Byte

The limits are compared to the temperature measurement results (TINT) and have been exceeded if

(TINT ≤ TL or TINT > TH). If either limit is exceeded then the appropriate bit is set high in the status

The THERM limit (TTH) is a single byte value set by the THERM Limit register. Excee ding the THERM

limit asserts the ADDR/THERM signal as described in Section 4.4 on page 11. When the

ALERT/THERM2 pin is configured as THERM2, then exceeding the high limit asserts this pin.

4.11 THERM Hysteresis Register

The THERM hysteresis register holds a hysteresis value that determines the de-assertion of THERM

as shown in Figure 4.4 on page 12. It defaults to 10°C and can be set by the user at any time after

power up. When the ALERT/THERM2 pin is configured as THERM2, then the hysteresis value also

impacts the de-assertion of THERM2.

4.12 One-Shot Register

Writing to the one-shot register while in standby mode initiates a conversion and comparison cycle.

The EMC1001 will execute a temperature measurement, compare the data to the limit registers and

return to the standby mode. A write to the one-shot register will be ignored if it occurs while the

EMC1001 is in run mode.

4.13 SMBus Timeout Enable

The EMC1001 has an SMBus timeout feature. Bit 7 of the SMBus Timeout Enable register enables

this function when set to 1 (the default setting is 0). When this feature is enabled, the SMBus will

timeout after approximately 25ms of inactivity.

1.5°C SMBus Temperature Sensor in Miniature SOT-23

Datasheet

Revision 1.6 (01-29-07) 16 SMSC EMC1001

DATASHEET

Chapter 5 Package Outline

Figure 5.1 EMC1001, 6 Pin SOT Package Outline; 1.6mm Body Width, 0.95mm Pitch

SEATING PLANE

ccc C

DETAIL "A" (SCALE: 2/1)

GAUGE PLANE

0.25

SIDE VIEW

3-D V IEWS

INDEX AREA

(D/2 x E1/2)

24 4

123

N = 5 LEADS N = 6 LEADS

NOTES:

1. "N" IS THE TOTAL NUMBER OF LEADS .

2. TRU E POSITION SPREAD TOLER ANCE IS ± 0.10mm AT MAXIMUM MATERIAL CONDITION.

3. PACKAGE BODY DIMENSION "D" DOES NOT INCLUDE MO LD F L AS H, P ROT RUS IO NS OR

GATE BURRS. MAXIMUM MOLD FLASH, PROTRUSIONS OR G AT E BU RRS I S 0 . 2 5 m m P E R

END. DIMENSION "E1" DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSION.

MAXIMUM INTERLEAD FLASH OR PROTRUSION IS 0.25 mm PER SIDE. "D1" & "E1"

DIMENSIONS ARE DET ERMINED A T DATUM PLANE "H".

4. DIMENSIONS "b" & "c" APPLY TO THE FLAT SECTION OF T H E LEAD BET WEEN 0.08 TO

0.15 mm FROM THE LEAD TIP.

5. DETAILS OF PIN 1 IDENTIFIER ARE OPTIONAL, BUT MUST BE LOCATED WITHIN THE

INDEX AREA INDICATED (SEE TOP VIEW).

6. FIVE LEAD PACKAGE IS A VERSION O F 6 LEAD PACKAGE, WHERE LEAD #5 HAS BEEN

REMOVED FROM 6 LEAD PACKAGE.

e5X b

SEE DETAIL "A"

TOP VIEW END VIEW

A2 A

A INITIAL RELEASE 7 /07/04 S.K.ILIEV

DECIMAL

X.X

X.XX

X.XXX

MATERIAL

FINISH

STD C OMPLIANCE

THIRD AN GLE PR OJEC TI ON

PRINT WITH "SCALE TO FIT"

DO N OT SCAL E D RAWING

APPROVED

ANGULAR

UN LES S OTHERWISE SPECIFIED

DIMENSIONS ARE IN MILLIMET ERS

AND TOLERANCES ARE:

DIM AND TOL PER ASME Y14.5M - 1994

DRAWN

CHECKED

NAME

SCALE

80 ARKAY DRIVE

HAUPPAUGE, NY 11788

USA

DW G NUMBER

TITLE

DATE

SHEET

REV

REVISION HISTORY

DESCRIPTIONREVISION RELEASED BYDATE

S.K.ILIEV

±1°

±0.025

±0.05

±0.1

7/07/04 1:1

7/06/04

7/06/04 A

JEDEC: MO-178 / AA, AB 1 OF 1

1.6mm BODY WIDTH, 0.95mm PITCH

PACKAGE OUTLINE: 5/6 PIN SOT

MO-5/6 SO T- 2.9x1.6