.
Features
•DC/DC Step-up Converter (BOOST) 3.3V to 5.2V, 1A, up to 90% Efficiency. Can be Used
as BUCK/BOOST in SEPIC Configuration
•DC/DC Step-down (BUCK) Synchronous Converter 0.9V to 3.4V, 500mA, up to 90%
Efficiency, Pulse Skipping Capabilities for High Efficiency at Light Load Currents
•Two Low-Drop-Out Regulators 1.3V, 1.5V to 1.8V, 2.5V to 2.8V (100 mV Step), 3.3V,
200 mA Maximum Load
•Ultra-low Power Real-time Clock (RTC) and Backup Battery Management
– 2.6V RTC LDO for Backup Battery Charging
– 32 kHz Crystal RTC Oscillator (1 µA)
– RTC Circuit for Time and Date Information
•Activation of the Power Management Modules via Dedicated Enable Pin
•Automatic Start-up Sequences, POK Signal Indicating When Start-up is Completed
•Activation and Control of the Power Management Modules in Dynamic Mode (via SPI or
TWI) or in Static Mode (On/Off of the Four Power Supplies)
•ITB Signal Indicating Short-circuits in DC/DC Converters
•Very Low Quiescent Current
•Minimum External Components Count
•Supply: from 2.8V to 5.25V (typ: Li-Ion Battery 3V to 4.2V)
•Available in a 32-pin 5x5 QFN Package
•Applications Include:
– WLAN Portable Devices
– Multimedia Devices
– Portable Music Players
1. Description
The AT73C224-x is a family of ultra low cost Power Management Unit, available in a
small outline QFN 5x5mm package.
The AT73C224-x family is optimized for portable applications, typically powered by a
Li-Ion battery. The AT73C224-x device is also suitable to operate from a standard
3.3V to 5.25V voltage rail. It includes four power supplies and a very low power Real-
time Clock (RTC). In normal mode (main battery present), the backup battery is
recharged through a 2.6V RTC LDO.
The AT73C224-x series offer different automatic start-up sequences (with varying
orders of power-on and specific default output values) and different soft management
modes: dynamic (via SPI or TWI) with register access or static, with access to power
on/off of the four power supplies.
Each AT73C224-x device is equipped with a very low power bandgap reference, low
power 32 kHz and 1 MHz oscillators and an internal LDO used to generate the internal
supply (VINT) equal to 2.8V. Auxiliary cells, such as a power-on reset (POR) and a
voltage monitor are used to control the system power-on (battery plugged in) and
power-off (battery unplugged).
The four power supplies are named: BOOST1, BUCK2, LDO3 and LDO4.
Table 1-1 lists the different devices available in the AT73C224-x series.
Power
Management
and Analog
Companions
(PMAAC)
AT73C224-A
AT73C224-B
AT73C224-C
AT73C224-D
AT73C224-E
AT73C224-F
AT73C224-G
AT73C224-H
4x Channels
Power Supply:
DC/DC BOOST
DC/DC BUCK
2x LDOs
RTC
6266A–PMAAC–08-Sep-08
2
6266A–PMAAC–08-Sep-08
AT73C224
For more details concerning the Automatic start-up sequences, see Section 5.2.
For more details concerning the Management Modes, see Section 5.3.
.
Table 1-1. AT73C224-x device series
Part Number Automatic Start-up Sequence
Order of power-on and output default values.
Management Mode Comments
AT73C224-A
1 - BUCK2= 1.8V
2 - LDO4 = 2.8V
3 - LDO3 = 2.7V
Dynamic BOOST1 can be activated after Start-up
sequence by a user command.
AT73C224-B
1 - BUCK2 = 1.2V
2 - LDO4 = 1.8V
3 - LDO3 = 1.8V
Dynamic BOOST1 can be activated after Start-up
sequence by a user command.
AT73C224-C
1 - LDO4 = 2.8V
2 - BUCK2 = 1.8V
3 - LDO3 = 2.7V
Dynamic BOOST1 can be activated after Start-up
sequence by a user command.
AT73C224-D
1 - LDO4 = 1.8V
2 - BUCK2 = 1.2V
3 - LDO3 = 1.8V
Dynamic BOOST1 can be activated after Start-up
sequence by a user command.
AT73C224-E
1 - BOOST11 = 5.2V
2 - LDO4 = 3.3V
3 - LDO3 = 3V
Dynamic
BUCK2 can be activated after Start-up
sequence by a user command.
LDO3 & LDO4 are supplied by BOOST1.
(See Section 4. “Application examples”, Figure
4-3 on page 7: Application Schematic 3.)
AT73C224-F
1 - BUCK2 = 1.8V
2 - LDO4 = 2.8V
3 - LDO3 = 2.7V
Static Same as AT73C224-A.
AT73C224-G
1 - LDO4 = 2.8V
2 - BUCK2= 1.8V
3- LDO3 = 2.7V
Static Same as AT73C224-C.
AT73C224-H
1 - BOOST1 = 5.2V
2 - LDO4 = 3.3V
3 - LDO3 = 3V
Static Same as AT73C224-E.
3
6266A–PMAAC–08-Sep-08
AT73C224
2. Block Diagram
Figure 2-1. Block Diagram
VDD3 VDD1
VSENSE1
DL1
VO1
VDD2
SW2
GND2
VO2
GND/AVSS
VO3
GNDANA
VDD4
VO4
VBAT_LDORTC
VBACKUP
XIN
XOUT
VDDIO
CK32
D1
D2
D3
D4
POK
ITB
VBG
VDD0
Die
Paddle
EN VINTVCAPP VCAPN
2
1
3
23
24
10
32
30
31
29
25
26
27
28
13
14
15
8
6
12 4 75
11
17
16
9
18
20
21
22
LDO3
VOUT
1.3V
1.5V-1.8V
2.5V-2.8V
3.3V
ILOAD
200 mA
LDO4
VOUT
1.3V
1.5V-1.8V
2.5V-2.8V
3.3V
ILOAD
200 mA
VBG
POR RTC
RTC LDO
RTC OSC
POR,
VMON
(Voltage Monitor)
LPVBG
(Low power VBG)
VINT
Regulator
Digital
Interface
(TWI / SPI)
PMC
Status
Register
BOOST1
VOUT
3.3V-5.2V
ILOAD
1A
BUCK2
VOUT
0.9V-3.4V
ILOAD
500 mA
P
N
OSC 900kHz
4
6266A–PMAAC–08-Sep-08
AT73C224
3. Pinout
Table 3-1. AT73C224 Pinout
Pin Name I/O Pin # Type Function Comments
VO3 O 1 Analog LDO3 output voltage Ext. 2.2 µF capacitor (mandatory)
VDD3 PS 2 Power LDO3 supply voltage
GNDANA PS 3 Ground Analog ground
VCAPP I/O 4 Analog Not connected
VINT PS 5 Power Output of the internal LDO Ext. 470 nF capacitor (mandatory)
VDD0 PS 6 Analog Supply of the internal LDO Must be connected to the main
battery (mandatory)
VCAPN I/O 7 Analog Not connected
VBG O 8 Analog Bandgap reference voltage Should not be resistively loaded
VDD2 PS 9 Power BUCK2 supply voltage
VBAT_LDORTC PS 10 Power LDO_RTC Supply voltage Must be connected to the main
battery (mandatory)
VO2 I 11 Analog BUCK2 output voltage
EN I 12 Digital Enable signal Internal 100 KΩ pull up
D4 I 13 Digital Digital interface Internal 100 KΩ pull up
POK O 14 Digital Power Ok: indicates when start-up is completed
ITB/RDY I/O 15 Digital User Interrupt, GPIO and Shutdown control Internal 100 KΩ pull up
SW2 O 16 Analog BUCK2 inductor (NMOS switcher output)
GND2 PS 17 Ground BUCK2 ground
VO1 I 18 Analog BOOST1 output voltage
DH1 O 19 Analog Not connected
DL1 O 20 Analog BOOST1 NMOS control signal
VSENSE1 I 21 Analog BOOST1 current limitation sense voltage
VDD1 PS 22 Power BOOST1 supply voltage Must be connected to the main
battery
VDD4 PS 23 Power LDO4 supply voltage
VO4 O 24 Analog LDO4 output voltage Ext. 2.2 µF capacitor (mandatory)
VDDIO PS 25 Digital
supply Supply voltage for Digital I/O
D1 I 26 Digital Digital interface open drain
D2 I/O 27 Digital Digital interface open drain
D3 I 28 Digital Digital interface open drain
CK32 O 29 Digital 32 kHz RTC output clock
XOUT I/O 30 Analog RTC crystal oscillator output
XIN I/O 31 Analog RTC crystal oscillator input
VBACKUP O 32 Analog Backup Battery and RTC supply
GND/AVSS PS 33 Ground Main GND and AVSS ground die paddle connected to ground
(mandatory)
5
6266A–PMAAC–08-Sep-08
AT73C224
4. Application examples
Figure 4-1. Application Schematic 1: Microcontroller with 5V VBUS for 2 USB Host Transceivers
In the Application Schematic 1, the AT7373C224-A is used: the BOOST(VO1) supplies the
“VBUS” of two USB transceivers, the BUCK(VO2) supplies the digital core of the microcontroller,
the LDO3 supplies the I/Os of the microcontroller and LDO4 supplies analog cells, such as aux-
iliary ADC or PLL.
For external components, see Table 4-1.
AT73C224-A Microcontroller
VDD1
VSENSE1
DL1
DH1
VO1
VDD2
SW2
GND2
VO2
GND/AVSS
VO3
GNDANA
VDD4
VO4
VBAT_LDORTC
VBACKUP
XIN
XOUT
VDDIO
CK32
D1
D2
D3
D4
POK
ITB/RDY
VBG
VDD0
Die
Paddle
EN
VCAPN
VCAPP
VINT
VBAT
VBAT
VO1
VDD3
VBAT
Pushbutton
uP uP uP
nc
nc
nc
ITB/RDY
uP
ITB/RDY
VDDIO
(AUX ADC, PLL)
USB HOST
transceiver
USB HOST
transceiver
VCORE SPI / TWI
VO2
VBAT
VBAT
BUCK2 = 1.8V
RST
SCK / TWCK
SDO / TWD
D1 D2 D3 D4
SDI /Adrress
SCS / GND
POK
R2
C11
C8
C14
C3
C5
C10
C7 C13
C2
L2
Q1
L1 D1
R1
C1
C6
C4 C9
C12
Rechargeable
Backup
Battery
(NBL type)
VBAT uP uP
X1
BOOST1 = 5V
(VBUS USB)
LDO4 = 2.8V
LDO3 = 2.7V
3V
to
4.2V
VBAT
1
32
C16
Li-Ion
Battery
6
6266A–PMAAC–08-Sep-08
AT73C224
Figure 4-2. Application Schematic 2: Supply of a Microprocessor and External Analog Cells
In the Application Schematic 2, the AT73C224-B is used: the BOOST (VO1) supplies the
“VBUS” of one USB transceiver and supplies also LDO3 and LDO4. The BUCK(VO2) supplies
the digital core of the microcontroller and the LDOs supply the I/Os and Analog cells, such as
auxiliary ADC or PLL.
For external components, see Table 4-1.
AT73C224-B
Microcontroller
Analog Cells
VDD1
VSENSE1
DL1
DH1
VO1
VDD2
SW2
GND2
VO2
GND/AVSS
VO3
GNDANA
VDD4
VO4
VBAT_LDORTC
VBACKUP
XIN
XOUT
VDDIO
CK32
D1
D2
D3
D4
POK
ITB/RDY
VBG
VDD0
Die
Paddle
EN
VCAPN
VCAPP
VINT
VBAT
VBAT
VO1
VDD3
VBAT
BUTTON
uP uP uP
nc
nc
ITB/RDY
uP
ITB/RDY
VDDIO
VCORE
SPI / TWI
VO2
nc
VBAT
VO4
VBAT
VBAT
BUCK2 = 1.2V
RST
SCK / TWCK
SDO / TWD
D1 D2 D3 D4
SDI /Adrress
SCS / GND
POK
R2
C11
C8
C14
C3
C5
C10
C7 C13
C2
L2
L1
R1
C1
C6
C4 C9
C12
Rechargeable
Backup
Battery
(NBL type)
VBAT uP uP
X1
Q1
BOOST1 = 5V
LDO4 = 1.8V
D1
3V
to
4.2V
1
32
C16
BOOST1 = 5V
Li_Ion
Battery
7
6266A–PMAAC–08-Sep-08
AT73C224
Figure 4-3. Application Schematic 3: BOOST in SEPIC Configuration (BUCK/BOOST)
In the Application Schematic 3, the BOOST (VO1) is in SEPIC configuration (BUCK/BOOST)
and generates a 3.3V output voltage for analog cells. The BUCK (VO2) supplies the core of the
microcontroller, and LDO4 supplies the I/Os.
Note that, in the SEPIC configuration, the maximum load current on VO1 should not exceed 300
mA.
For external components, see Table 4-1.
AT73C224-B
Microcontroller
Analog Cells
VDD1
VSENSE1
DL1
DH1
VO1
VDD2
SW2
GND2
VO2
GND/AVSS
VO3
GNDANA
VDD4
VO4
VBAT_LDORTC
VBACKUP
XIN
XOUT
VDDIO
CK32
D1
D2
D3
D4
POK
ITB/RDY
VBG
VDD0
Die
Paddle
EN
VCAPN
VCAPP
VINT
VBAT
VBAT
VO1
VDD3
VBAT
BUTTON
uP uP uP
nc
nc
ITB/RDY
uP
ITB/RDY
VDDIO
VCORE
SPI / TWI
VO2
nc
VBAT
VO4
VBAT
VBAT
BUCK2 = 1.2V
RST
SCK / TWCK
SDO / TWD
D1 D2 D3 D4
SDI /Adrress
SCS / GND
POK
R2
C11
C8
C14
C3
C5
C10
C7 C13
C2
L2
L1
R1
C1
C6
C4 C9
C12
Rechargeable
Backup
Battery
(NBL type)
VBAT uP uP
X1
C15
L3
Q1
BOOST1 = 3.3V
LDO4 = 1.8V
D1
3V
to
4.2V
1
32
C16
BOOST1 = 3.3V
Li_Ion
Battery
8
6266A–PMAAC–08-Sep-08
AT73C224
Table 4-1. External Components
Schematic reference Reference Manufacturer Value
C1 Tantalum TPS Case B AVX®100 µF
C2 Tantalum TPS Case A AVX 33 µF
C3, C4 GRM155R60J225ME15
C1005X5R0J225MT
Murata®
TDK 2.2 µF
C6 GRM21BR60J226ME39
C2012X5R0J226MT
Murata
TDK 22 µF
C5, C7, C8, C9, C11, C13 GRM155R60J105KE19
C1005X5R0J105KT
Murata
TDK 1 µF
C10 GRM155R61A104KA01
C0603X5R0J104KT
Murata
TDK 100 nF
C12, C14 GRM155R60J474KE18
C1005X5R1A474KT
Murata
TDK 470 nF
C15 GRM188R60J475KE19
C1608X5R0J475KT
Murata
TDK 4.7 µF
C16 GRM188R60J106ME47
C1608X5R0J106MT
Murata
TDK 10 µF
L1 744773022 Wurth® Elektronik 2.2 µH
L1, L3 (in SEPIC config.) 744773068 Wurth Elektronik 6.8 µH
L2 B82467-G0682-M Epcos®6.8 µH
D1 MBRM120LT1 On Semiconductor®
Q1 Si1470DH Vishay®
X1 FX135B-327 Fox 32.768 kHz
R1 (can be printed on the
board (Cu line)) LR2010R050J Welwyn 50 mΩ
R2 MR-CRG0402J2k2 Tyco™ Electronics 2 kΩ
9
6266A–PMAAC–08-Sep-08
AT73C224
5. Detailed Description
The AT73C224-x is a family of Power Management Units with four power supplies and an ultra
low-power Real-time Clock.
By choosing a specific ordering code “x” from A to H, different automatic start-up sequences and
management modes can be selected.
The start-up sequence includes the order of power-on, as well as the default value of the power
supplies (see Section 5.2 ”Automatic Start-up Sequences and Shut-down”). The user can after-
wards change this default value via SPI or TWI, if the dynamic mode has been chosen (see
Section 5.3 ”Digital Control and Protocol”).
5.1 Core
The core of the AT73C224-x device integrates the following blocks:
• Power-On-Reset for the backup battery.
• Internal switch and LDO dedicated to the backup battery. The output of the LDO_RTC is set
to 2.6V and the switch is on when the main battery higher than 2.8V (charge of the backup
battery).See Section 7.7 for electrical details.
• Real-Time-Clock digital bloc + 32 kHz oscillator.
• Power-On-Reset for the main battery.
• Voltage Monitor (VMON) of the main battery.
• Digital Power Management Control (PMC) for automatic start-up sequences. Digital output
POK indicates when start-up is completed, whereas ITB digital output signal informs the user
(typically the microcontroller) of a default in the DC/DCs (short-circuit) or too low main battery
value.
• TWI and SPI protocol blocs.
• DC/DC Step-up converter BOOST1: A 3.3V to 5.2V(100 mV step), 1A, asynchronous DC/DC
Step-up Converter available for overall system requirements. The DC/DC can be
implemented through proper external components in BUCK/BOOST (SEPIC) configuration.
The output voltage can be programmed via the internal registers. BOOST1 is supplied
directly by the battery.
• DC/DC Step-down converter BUCK2: A 0.9V to 3.4V, 500 mA fully integrated synchronous
PWM DC/DC Step-down Converter. The output voltage can be programmed via the internal
registers. A Pulse Skipping mode is available in order to improve efficiency at very light load
current values. In order to guarantee very low supply voltage functionality, the controller is
supplied by the max voltages between the main battery and the output of BOOST1 (VO1).
BUCK2 can be directly supplied by the battery or by the output of BOOST1.
• LDO3: A 1.3V, 1.5V to 1.8V (100 mV of step), 2.5V to 2.8V (100 mV of step), 3.3V, 200 mA –
Low Drop out regulators. The output voltage can be programmed via the internal registers.
LDO3 can work with supply from 1.8V up to 5.5V. This LDO can be supplied by the battery, by
the output of BOOST1, or by the output of BUCK2.
• LDO4: same functionality than LDO3.
• Main Bandgap: 1.18V reference voltage.
• 900 kHz Oscillator.
• Internal LDO (VINT) at 2.8V for internal supply.
10
6266A–PMAAC–08-Sep-08
AT73C224
5.2 Automatic Start-up Sequences and Shut-down
5.2.1 Start-up/Wakeup
If the backup battery (only) is present, the RTC is running (1.2 µA). This mode is called “Backup
mode”. When the main battery is plugged in and voltage is higher than 2.8V, the LDO_RTC
recharges the backup battery through an internal switch (if the main battery is lower than 2.8V,
nothing happens, RTC still running). This mode is called “Standby mode”. Note that when the
battery is plugged in (and higher than 2.8V), a reset of the RTC is performed only if the backup
battery was lower than 1.8V.
Now, the system waits for wake-up information coming from the pushbutton (EN pin) or an RTC
alarm. When one of the previous conditions occurs, the automatic start-up sequence starts
(without any external commands).
Different automatic start-up sequences can be chosen from the AT73C224-x family (see Figure
5-1 on page 11 and Figure 5-2 on page 12).
When the automatic start-up sequence has been completed, the POK signal (which is an open
drain signal) goes high, thus implementing a sort of POR for the user (i.e., a microcontroller) and
enters into “Normal mode”.
Note: Power On is controlled by default by an external pushbutton, connected on EN pin (the EN
pad has an internal 100 kΩ pull up). A switch can also be used as shown bellow but should be a
request from the customer
.
5.2.2 Shut-down
Static and Dynamic modes are explained in detail in Section 5.3.
5.2.2.1 Static Mode
In Static mode, the Power-off condition is an OR between the following conditions: main battery
lower than 2.8V or electrical default in the DC/DC (short-circuit). When Power-off condition
occurs, POK signal is cleared, then the AT73C224-x device waits for the signal ITB/RDY to shut
down all power supplies.
5.2.2.2 Dynamic Mode
In Dynamic mode, Power-off condition is an OR between the following conditions: electrical
default in the DC/DC (short-circuit) or software shutdown. When main battery lower than 2.8V,
an interrupt is generated on signal ITB/RDY. It is the responsibility of the host microcontroller to
perform a software shut-down by properly writing the AT73C224-x device registers through the
serial interface. After that, the POK signal is cleared, and all is turned off. A check on the push-
button is then performed to assure that it has been released, thus avoiding continuous on-off-on
behavior. The “normal” shutdown is performed by software. Note that the microcontroller has to
write the proper register to enable the power off (see Section 6. ”Register Tables”).
EN
(Default: Pushbutton)
EN
(On request: switch)
11
6266A–PMAAC–08-Sep-08
AT73C224
Figure 5-1 illustrates the complete automatic start-up sequence of the AT73C224-A and
AT73C224-F, whereas Figure 5-2 illustrates the automatic start-up sequence of the other
AT73C224-x device versions.
Figure 5-1. Start up Sequence of the AT73C224-A and AT73C224-F
3ms
BOOST1
User Command:
. AT73C224-A: Through Dynamic mode (using TWI or SPI)
. AT73C224-F: Through Static mode (using D1 pin)
45ms typ
3ms
3ms
EN (Wake-up of the system)
(Pushbutton)
VINT
(internal supply)
PWRGDINT
(internal- Vth = 1.6V)
POK -> uP
(Start-up sequence
completed)
VMON
(internal Vth = 2.8V)
POR
(internal Vth = 1.6V)
VBAT
36 ms typ.
VBG
30 ms min
Automatic Start-up Sequence:
BUCK2
(Default value: 1.8V)
LDO4
(Default value: 2.8V)
LDO3
(Default value: 2.7V)
12
6266A–PMAAC–08-Sep-08
AT73C224
Figure 5-2. Automatic Start-up Sequence of all Other Versions of the AT73C224-x Device Series
BOOST1
User Command:
. AT73C224-B: Through Dynamic mode (using TWI or SPI)
BOOST1
User command:
. AT73C224-C: Through Dynamic mode (using TWI or SPI)
. AT73C224-G: Through Static mode (using D1 pin)
BOOST1
User Command:
. AT73C224-D: Through Dynamic mode (using TWI or SPI)
BUCK2
User command:
. AT73C224-E: Through Dynamic mode (using TWI or SPI)
. AT73C224-H: Through Static mode (using D2 pin)
3ms
3ms
AT73C224-B, AT73C224-G
BUCK2
(Default value: 1.2V)
LDO4
(Default value: 1.8V)
LDO3
(Default value: 1.8V)
AT73C224-C, AT73C224-H
BUCK2
(Default value: 1.8V)
LDO4
(Default value: 2.8V)
LDO3
(Default value: 2.7V)
AT73C224-D, AT73C224-I
BUCK2
(Default value: 1.2V)
LDO4
(Default value: 1.8V)
LDO3
(Default value: 1.8V)
AT73C224-E, AT73C224-J
BOOST1
(Default value: 5.2V)
LDO4
(Default value: 3.3V)
LDO3
(Default value: 3V)
POK (Automatic Start-up
sequence completed)
3ms
V
13
6266A–PMAAC–08-Sep-08
AT73C224
5.3 Digital Control and Protocol
The AT73C224-x family offers a choice of devices in static mode or dynamic mode (see Table 1-
1 on page 2). In dynamic mode, the user can manage the chip via SPI or TWI. The selection
between SPI or TWI is done at start-up via the D4 pin (see Section 5.3.2 on page 14).
5.3.1 Static Mode
When the AT73C224-x is established in Static Mode, the digital interface signals, D1 to D4,
directly drive the enable of the four supplies. During start-up, these enable signals are driven by
the internal state machine. To ensure a safe transition between the start-up state and the estab-
lished state, a handshake protocol must be respected. This transition period is especially
important in a microcontroller environment, as the microcontroller controlling the D1-D4 signals
may require an unknown period of time to actually drive these pins.
In Static Mode, the ITB/RDY pin is configured as an input with controllable pull-up resistor. When
the internal state machine completes the supply start-up, it latches the value of ITB/RDY and
then sets the POK signal to 1. This means that start-up is accomplished. The state machine then
checks for changes on ITB/RDY. If no changes are detected, the control of the four supply chan-
nels remains with the state machine. If a change is detected the internal pullup is disconnected
and the control is passed on to D1-D4, with the assignment shown in Table 5-2 below.
The illustrations in Figure 5-3, Figure 5-5 and Figure 5-5 represent possible static mode
scenarios.
Figure 5-3. Fully Static Mode
Since ITB/RDY is 1 or open (weak internal pullup), the state of each supply channel is deter-
mined by the internal state machine (Automatic Start-up sequence and default values for the
three power supplies). In this configuration, the 4th power supply is off and can not be used. D1-
D4 is not considered, but must be valid. The POK signal can be used as a global system reset.
Table 5-1. D1-D4 Signal Assignment
Digital Interface Signal Supply Enable
D1 Enables BOOST1
D2 Enables BUCK2
D3 Enables LDO3
D4 Enables LDO4
D1
D2
D3
D4
ITB/RDY
POK
0 or 1
Power OK
Open or 1
14
6266A–PMAAC–08-Sep-08
AT73C224
Figure 5-4. Configurable Static Mode
The state of each channel is determined by the internal state machine during the start-up
sequence. POK is looped back onto ITB/RDY. When this signal changes from 0 to 1 (i.e., the
start-up is completed), the control of each supply channel is passed on to D1-D4. This allows
changing the output values defined by the state machine. This mode can be used when the 4th
channel is needed.
Figure 5-5. GPIO (µC Controlled)
When the system is powered, the microcontroller is not necessarily well configured and may be
unable to drive D1-D4 correctly. Since ITB/RDY is not actively controlled, its state is an unknown
logic level. If ITB/RDY is in hi-Z, the weak internal pullup pulls the level to 1. The power channels
are controlled by the internal state machine. After some initialization time, the microcontroller
configures its GPIOs to drive D1-D4 as wished. At the end of the software configuration, the
microcontroller changes the level of ITB/RDY to 0 in order to get control on the four power chan-
nels through D1-D4.
5.3.2 Dynamic Mode
For the devices of the AT73C224-x family that work in dynamic mode, supply management can
be performed by the SPI or TWI digital interface. Selection between the two digital interfaces is
done through D4 pin when the AT73C224-x is enabled. Pin D4 is a digital input pin that features
a controllable pull-up resistor with active low control signal. When the AT73C224-x starts, the
pullup is disabled until a push button event is detected. The state machine enables the pull-up
resistor on D4, waits for a time and then checks back on the value on the pad.
• If D4 is high (i.e., the level externally applied on D4 is HZ or logic 1), SPI interface is selected.
D4 will become SCS.
• If D4 is low (i.e., D4 is externally grounded), TWI interface is selected. D4 is not used.
After signal dynamic has been determined the state machine disables the pull-up resistor to
save power and the D4 pin can be normally used (if SPI has been selected).
D1
D2
D3
D4
ITB/RDY
POK
01
Power OK
D1
D2
D3
D4
ITB/RDY
POK
I/O
I/O
I/O
I/O
I/O
µC
RST or NMI
15
6266A–PMAAC–08-Sep-08
AT73C224
The selection between SPI versus TWI is performed once, each time the start-up sequence is
executed. A timing diagram of the interface selection is shown in Figure 5-6. Care must be taken
to leave enough time between the activation of the pullup and the moment when D4 is sampled
back. This time is necessary to load the capacitance of the net layout where D4 is connected
through the pull-up resistor (100 kΩ typ.). This time is in the order of magnitude of 1 µs (10 pF *
100 kΩ), i.e. only a few cycles of the 900 kHz oscillator are needed.
Figure 5-6. Dynamic Mode Interface Selection
Note: 1. On D4, I = Input pad with controllable pull-up resistor.
5.3.2.1 SPI Operation
When SPI mode is selected, the control interface to the AT73C224-x chip is a 4-wire interface
modeled after commonly available microcontroller and serial-peripheral devices. The interface
consists of a serial clock (SCK), chip select (SCS), serial data input (SDI) and serial data output
(SDO). Data is transferred one byte at a time with each register access consisting of a pair of
byte transfers. Figure 5-7 below illustrates read and write operations in SPI mode.
D4
D4 pull-up control signal
Hz SPI selected, D4 => SCS
D4
D4 pull-up control signal
TWI selected
dynamic
dynamic
SCS = Serial Chip Select
Table 5-2. Digital Interface Selection
Digital Signal
Interface Pad
SPI Selection TWI Selection
Signal Direction Signal Direction
D1 I SCK In TWCK In
D2 BIDIR SDO Out TWD I/O
D3 I SDI In Select the 7-bit
fixed address In
D4(1) I SCS In grounded -
16
6266A–PMAAC–08-Sep-08
AT73C224
Figure 5-7. SPI Read and Write Operations
The first byte of a pair is the command/address byte. The most significant bit of this byte indi-
cates register read when 1 and register write when 0. The remaining seven bits of the
command/address byte indicate the address of the register to be accessed.
The second byte of the pair is the data byte. During a read operation, the SDO becomes active
and the 8-bit contents of the register are driven out MSB first. The SDO will be in high imped-
ance on either the falling edge of SCK following the LSB or the rising edge of SCS, whichever
occurs first.
SDI is a don't care during the data portion of read operations. During write operations, data is
driven into the AT73C224-x via the SDI pin, MSB first. The SDO pin will remain in high imped-
ance during write operations. Data always transitions with the falling edge of the clock and is
latched on the rising edge. The clock should return to a logic high when no transfer is in
progress.
•Continuous clocking: In normal operation, the SCK should not transition out of byte transfer
periods. However, in test mode, the SCK is used as the main clock. This implies that all data
transfers must be controlled by the assertion of the SCS pin.
•3-wire operation: SDI and SDO can be treated as two separate lines or wired together if the
master is capable of tri-stating its output during the data-byte transfer of a read operation.
•SCK vs internal clock rates: It is very likely that the bit rate commanded by SCK will be
much higher than the internal clock (900 kHz/64) used to read and write the registers. This
implies that a minimal delay between byte transfers must be imposed to allow some time to
decode the address and actually access the physical register. It is not acceptable to sample
SCK with the internal clock.
0A6A5A4A3A2A1A0 D7D6D5D4D3D2D1
SCK
SCS
SDI
SDO
D0
SPI Write
SCK
SCS
SDI
SDO
1 A6 A5A4 A3A2A1 A0
Hz
SPI Read
D7 D6 D5 D4 D3 D2 D1 D0
Hz
17
6266A–PMAAC–08-Sep-08
AT73C224
5.3.2.2 TWI Operation
The TWI interface allows a microcontroller to proceed to read or write accesses to the internal
registers of the AT73C224-x. Unlike the SPI, the TWI operation is based on a standard which
defines a data-link layer and an addressing scheme. The TWI implementation used in the
AT73C224-x conforms to this standard, with the following restrictions:
• slave only
• bit rate: 400 kbps max
• 7-bit fixed address: the default value is 1001001 (D3 is high). But the external D3 bit can
modify it. When D3 is low, the 7-bit fixed address is 1001000.
• TWCK is an input pin for the clock
• TWD is a bidirectional pin driving (open drain with external resistor connected to VDDIO) or
receiving the serial data.
The data put on TWD line must be 8 bits long. Data is transferred MSB first. Each byte must be
followed by an acknowledgement. Each transfer begins with a Start condition and terminates
with a STOP condition.
• A high-to-low transition on TWD while TWCK is high defines a START condition.
• A low-to-high transition on TWD while TWCK is high defines a STOP condition.
Figure 5-8. TWI Start/Stop Condition
Figure 5-9. TWI Protocol
After the host initiates a START condition, it sends the 7-bit slave address, as defined above, to
notify the slave device. A Read/Write bit follows (Read = 1, Write = 0). The device acknowledges
each received byte. The first byte sent after device address and R/W bit is the address of the
device register the host wants to read or write. For a write operation, the data follows the internal
address. For a read operation, a repeated START condition needs to be generated followed by
a read on the device.
Write and Read operations are shown in Figure 5-8 and Figure 5-9.
START STOP
TWD
TWCK
START
TWD
TWCK
STOP
Address Data AckAckDataAckR/W
18
6266A–PMAAC–08-Sep-08
AT73C224
The TWI abbreviations are defined below.
Figure 5-10. Write Operation
Figure 5-11. Read Operation
5.3.3 Interrupt Controller
In dynamic mode, the ITB/RDY pin is an output and operates as an interrupt to an external
microcontroller. The output logic is active low (a 0 level means interrupt).
Several sources can potentially trigger an interrupt:
• the RTC, when a real-time alarm event occurs (see Section 7.8 ”Real-time Clock (RTC)” for
more details)
• the push-button, when its state changes
• the power monitor, when it detects a failure or main battery lower than 2.7V
• the boost, when it detects a failure
• the buck, when it detects a failure
Each of these sources can be individually masked to disable the corresponding interrupt. All the
interrupt logic can also be globally disabled when the microcontroller needs to enter an uninter-
ruptible state. The interrupt enable/disable logic is controlled through two independent registers.
Refer to Section 6. ”Register Tables” for detailed register and bit assignment. IRQ_EN is used to
enable the interrupts, while IRQ_DIS is used to disable the interrupts. This strategy allows the
controlling software to handle the interrupt mask completely independently for each interrupt
source while avoiding read-modify-write operations. The register IRQ_MSK can be read to know
the current interrupt mask.
The sequence shown below in Table 5-3 shows an example of interrupt masking/unmasking.
S = Start A = Acknowledge
P = Stop N = Not Acknowledge
W = Write ADDR = Device Address
R = Read IADDR = Internal Address
TWD S ADDR AW IADDR AAPDATA
TWD S ADDR AW IADDR A S ADDR R A N PDATA
Table 5-3. Interrupt Masking/Unmasking
Action What it Does Contents of IRQ_MSK
Reset Disables all interrupts individually and globally. 00000000
Write 00000101 in IRQ_EN Enables the RTC interrupt and the power failure interrupt individually. The
interrupts are still globally masked, no interrupt can be triggered yet. 00000101
Write 00000000 in IRQ_EN Nothing happens, only bits set at one have an effect. 00000101
Write 10000000 in IRQ_EN Enables the interrupts globally. The ITB pin will toggle to 0 if either the
RTC or the power monitor requests an interrupt. 10000101
Write 00000001 in IRQ_DIS Disables the RTC interrupt. The power failure interrupt remains active. 10000100
19
6266A–PMAAC–08-Sep-08
AT73C224
Once the interrupt request is active on the ITB/RDY pin, the microcontroller has to handle it. To
determine the reason for being interrupted, it reads the interrupt status register IRQ_STA (this
action resets ITB/RDY). In this register, each potential interrupt source has a bit which indicates
if it is responsible for triggering the request.
Once the source is identified, the microcontroller performs the handling routine in an application-
dependant manner. It then needs to acknowledge the interrupt source to avoid being interrupted
again for the same reason.
20
6266A–PMAAC–08-Sep-08
AT73C224
6. Register Tables
Default values appear beneath the bit fields in the register description tables that follow.
6.1 System Registers
6.1.1 7-bit Fixed Address for TWI
Register Name: TWIADDR
Access Type: Read-only
Address: 0x01
• ADDR:
Reads the TWI address currently in use. This field can be used to check the connectivity of the TWI, or to identify the
AT73C224-x device. When ALT bit is 0, ADDR contains the alternate address (0x48). When ALT is 1, ADDR contains the
default address (0x49).
•ALT:
Indicates if the TWI address is the default or the alternate.
0: the default address is selected.
1: the alternate address is selected.
The reset value depends on the configuration of the fuses. When the fuses are blank, the reset value is 0 (manufacturing
default).
6.1.2 Button Status Register
Register Name: BT_SR
Access Type: Read-only
Address: 0x02
•Low:
0: the button input has not been seen low.
1: the button input has been seen low.
• High:
0: the button input has not been seen high.
1: the button input has been seen high.
76543210
ALT ADDR
11001001
76543210
––––––HIGHLOW
00
21
6266A–PMAAC–08-Sep-08
AT73C224
6.1.3 Button Status Clear Command Register
Register Name: BT_SCCR
Access Type: Write-only
Address: 0x03
A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access.
•Low:
0: no effect.
1: clears LOW in BT_SR.
• High:
0: no effect.
1: clears HIGH in BT_SR.
6.1.4 Button Interrupt Enable Register
Register Name: BT_IER
Access Type: Write-only
Address: 0x04
A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access.
•Low:
0: no effect.
1: the button low interrupt is enabled.
• High:
0: no effect.
1: the button high interrupt is enabled.
76543210
––––––HIGHLOW
00
76543210
––––––HIGHLOW
00
22
6266A–PMAAC–08-Sep-08
AT73C224
6.1.5 Button Interrupt Disable Register
Register Name: BT_IDR
Access Type: Write-only
Address: 0x05
A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access.
•Low:
0: no effect.
1: the button low interrupt is disabled.
• High:
0: no effect.
1: the button high interrupt is disabled.
6.1.6 Button Interrupt Mask Register
Register Name: BT_IMR
Access Type: Read-only
Address: 0x06
•Low:
0: the button low interrupt is disabled.
1: the button low interrupt is enabled.
• High:
0: the button low interrupt is disabled.
1: the button low interrupt is enabled.
6.1.7 Software Shutdown Command Register
Register Name: SHUTDN
Access Type: Write-only
Address: 0x07
A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access.
0: no effect.
1: shutdown the whole chip.
76543210
––––––HIGHLOW
00
76543210
––––––HIGHLOW
00
76543210
–––––––LOW
0
23
6266A–PMAAC–08-Sep-08
AT73C224
6.2 PMU Registers
6.2.1 BOOST Command Register
Register Name: BST_CLR
Access Type: Read/Write
Address: 0x10
A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access.
•EN:
Writing EN to 1 starts the BOOST/SEPIC converter.
Writing En to 0 stops the BOOST/SEPIC converter.
(*): Default value depends on the chosen AT73C224-x device (see Section 5.2).
76543210
–––––––EN(*)
24
6266A–PMAAC–08-Sep-08
AT73C224
6.2.2 BOOST Configuration Register
Register Name: BST_CFG
Access Type: Read/Write
Address: 0x11
•ISHORT:
Selects the overcurrent threshold. When the external sense resistor is 50 mOhms, the lookup table below applies.
At the startup, it is recommended to put 1 Amp over current threshold in order not to generate a reset of the product.
76543210
–––– ISHORT
1011
ISHORT Threshold (Amps)
0000b 0.5
0001b 1.0
0010b 1.5
0011b 2.0
0100b 2.5
0101b 3.0
0110b 3.5
0111b 4.0
1000b 4.5
1001b 5.0
1010b 5.5
1011b 6.0
1100b 6.5
1101b 7.0
25
6266A–PMAAC–08-Sep-08
AT73C224
6.2.3 BOOST Voltage Register
Register Name: BST_VOLT
Access Type: Read/Write
Address: 0x12
•VOUT:
Selects the output voltage of the regulator following the table below. VOUT should always be higher than VDD1 in BOOS T
configuration (Application schematic 1). It can be programmed lower in SEPIC configuration (Application Schematic 2).
(*): Default value depends on the chosen AT73C224-x device (see Section 5.2). The chosen value should always be higher
than the supply of the cell (VDD1).
76543210
–– VOUT(*)
VOUT [5:0] VOUT [V] VOUT [5:0] VOUT [V]
000000 not permitted 010101 3.3
000001 not permitted 010110 3.4
000010 not permitted 010111 3.5
000011 not permitted 011000 3.6
000100 not permitted 011001 3.7
000101 not permitted 011010 3.8
000110 not permitted 011011 3.9
000111 not permitted 011100 4.0
001000 not permitted 011101 4.1
001001 not permitted 011110 4.2
001010 not permitted 011111 4.3
001011 not permitted 100000 4.4
001100 not permitted 100001 4.5
001101 not permitted 100010 4.6
001110 not permitted 100011 4.7
001111 not permitted 100100 4.8
010000 not permitted 100101 4.9
010001 not permitted 100110 5.0
010010 not permitted 100111 5.1
010011 not permitted 101000 5.2
010100 3.2 —
26
6266A–PMAAC–08-Sep-08
AT73C224
6.2.4 BUCK2 Control Register
Register Name: BCK_CTROL
Access Type: Read/Write
Address: 0x13
A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access.
•EN:
Writing EN to 1 starts the BUCK converter.
Writing EN to 0 stops the BUCK converter.
(*): Default value depends on the chosen AT73C224-x device (see Section 5.2).
• BYP:
Writing BYP to 1 puts the BUCK2 output voltage to VDD2.
Writing BYP to 0 configures the BUCK2 in Normal operation (default).
76543210
––––––BYPEN(*)
27
6266A–PMAAC–08-Sep-08
AT73C224
6.2.5 BUCK2 Configuration Register
Register Name: BCK_CFG
Access Type: Read/Write
Address: 0x14
•ISHORT:
Selects the overcurrent threshold. When the external sense resistor is 50 mOhms, the lookup table below applies.
•MODE:
Selects the PWM pulse skipping mode.
•SLIM:
Selects the power-up mode.
0: current limitation.
1: slow start.
76543210
OUTZ SLIM MODE ISHORT
11001000
ISHORT Threshold (Amps)
0000b 1.01
0001b 1.08
0010b 1.15
0011b 1.22
0100b 1.29
0101b 1.36
0110b 1.43
0111b 1.5
1000b 1.57
1001b 1.64
1010b 1.71
1011b 1.78
1100b 1.85
1101b 1.92
1110b 1.99
1111b 2.06
MODE Operation
00 Auto
01 PWM
10 Pulse skipping
11 Pass-through
28
6266A–PMAAC–08-Sep-08
AT73C224
•OUTZ:
Defines the state of the voltage output when the converter is off.
0: the output is forced to ground.
1: the output is left floating (Hz).
29
6266A–PMAAC–08-Sep-08
AT73C224
6.2.6 BUCK2 Voltage Register
Register Name: BCK_VOLT
Access Type: Read/Write
Address: 0x15
•VOUT:
Selects the output voltage of the regulator following the table below.
(*): Default value depends on the chosen AT73C224-x device (see Section 5.2).
76543210
––– VOUT(*)
VOUT [4:0] VOUT [V] VOUT [4:0] VOUT [V]
00000 0.9 10000 1.28
00001 1.0 10001 1.42
00010 1.1 10010 1.56
00011 1.2 10011 1.7
00100 1.3 10100 1.86
00101 1.4 10101 2.00
00110 1.5 10110 2.14
00111 1.6 10111 2.29
01000 1.7 11000 2.43
01001 1.8 11001 2.57
01010 1.9 11010 2.71
01011 2.0 11011 2.86
01100 2.1 11100 3.00
01101 2.2 11101 3.14
01110 2.3 11110 3.30
01111 2.4 11111 3.42
30
6266A–PMAAC–08-Sep-08
AT73C224
6.2.7 LDO3 Control Register
Register Name: LDO3_CTRL
Access Type: Read/Write
Address: 0x16
A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access.
•EN:
Writing EN to 1 starts the LDO3 regulator.
Writing EN to 0 stops the LDO3 regulator.
(*): Default value depends on the chosen AT73C224-x device (see Section 5.2).
6.2.8 LDO3 Configuration Register
Register Name: LDO3_CFG
Access Type: Read/Write
Address: 0x17
•OUTZ:
Defines the state of the voltage output when the regulator is off.
0: the output is forced to ground.
1: the output is left floating (Hz).
This bit should be at 1 when LDO is on.
•MODE:
0: RF mode, IMAX = 100 mA.
1: Smoother mode, IMAX = 200 mA.
76543210
–––––––EN(*)
76543210
–––––MODEOUTZ–
11
31
6266A–PMAAC–08-Sep-08
AT73C224
6.2.9 LDO3 Voltage Register
Register Name: LDO3_VOLT
Access Type: Read/Write
Address: 0x18
•VOUT
Selects the output voltage of the regulator following the table below.
(*): Default value depends on the chosen AT73C224-x device (see Section 5.2).
76543210
–––– VOUT(*)
VOUT [3:0] VOUT [V]
1000 1.3
0000 1.5
0001 1.6
0010 1.7
0011 1.8
0100 2.5
0101 2.6
0110 2.7
0111 2.8
1001 3.3
1010 4.9
others –
32
6266A–PMAAC–08-Sep-08
AT73C224
6.2.10 LDO4 Control Register
Register Name: LDO4_CTRL
Access Type: Read/Write
Address: 0x19
A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access.
•EN:
Writing EN to 1 starts the LDO4 regulator.
Writing EN to 0 stops the LDO4 regulator.
(*): Default value depends on the chosen AT73C224-x device (seeSection 5.2).
6.2.11 LDO4 Configuration Register
Register Name: LDO4_CFG
Access Type: Read/Write
Address: 0x1A
•OUTZ:
Defines the state of the voltage output when the regulator is off.
0: the output is forced to ground.
1: the output is left floating (Hz).
This bit should be at 1 when LDO is on.
•MODE:
0: RF mode, IMAX = 100 mA.
1: Smoother mode, IMAX = 200 mA.
76543210
–––––––EN(*)
76543210
–––––MODEOUTZ–
11
33
6266A–PMAAC–08-Sep-08
AT73C224
6.2.12 LDO4 Voltage Register
Register Name: LDO4_VOLT
Access Type: Read/Write
Address: 0x1B
•VOUT
Selects the output voltage of the regulator following the table below.
(*): Default value depends on the chosen AT73C224-x device (see Section 5.2).
76543210
–––– VOUT(*)
0111
VOUT[3:0] VOUT [V]
1000 1.3
0000 1.5
0001 1.6
0010 1.7
0011 1.8
0100 2.5
0101 2.6
0110 2.7
0111 2.8
1001 3.3
1010 4.9
others –
34
6266A–PMAAC–08-Sep-08
AT73C224
6.2.13 PMU Status Register
Register Name: PMU_SR
Access Type: Read-only
Address: 0x1C
•SHORT1:
0: no overcurrent condition.
1: an overcurrent condition has been detected on the BOOST/SEPIC1 converter.
•PG1:
0: no power good condition on BOOST/SEPIC1.
1: the power good condition has been met on BOOST/SEPIC1.
•PF1:
0: no power failure condition on BOOST/SEPIC1.
1: the power failure condition has been met on BOOST/SEPIC1.
•PG2:
0: no power good condition on BUCK2.
1: the power good condition has been met on BUCK2.
•PF2:
0: no power failure condition on BUCK2.
1: the power failure condition has been met on BUCK2.
76543210
– – PF2 PG2 – PF1 PG1 SHORT1
00000000
35
6266A–PMAAC–08-Sep-08
AT73C224
6.2.14 PMU Status Clear Command Register
Register Name: PMU_SCCR
Access Type: Write-only
Address: 0x1D
A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access.
•SHORT1:
0: no effect.
1: clears SHORT1 in the PMU_SR.
•PG1:
0: no power good condition on BOOST/SEPIC1.
1: clears PG1 in the PMU_SR.
•PF1:
0: no effect.
1: clears PF1 in the PMU_SR.
•PG2:
0: no effect.
1: clears PG2 in the PMU_SR.
•PF2:
0: no effect.
1: clears PF2 in the PMU_SR.
76543210
– – PF2 PG2 – PF1 PG1 SHORT1
–– –––
36
6266A–PMAAC–08-Sep-08
AT73C224
6.2.15 PMU Interrupt Enable Register
Register Name: PMU_IER
Access Type: Write-only
Address: 0x1E
A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access.
•SHORT1:
0: no effect.
1: the overcurrent detection interrupt on BOOST/SEPIC1 is enabled.
•PG1:
0: no effect.
1: the power good interrupt of BOOST/SEPIC1 is enabled.
•PF1:
0: no effect.
1: the power fail interrupt of BOOST/SEPIC1 is enabled.
•PG2:
0: no effect.
1: the power good interrupt of BUCK2 is enabled.
•PF2:
0: no effect.
1: the power fail interrupt of BUCK2 is enabled.
76543210
– – PF2 PG2 – PF1 PG1 SHORT1
––00–000
37
6266A–PMAAC–08-Sep-08
AT73C224
6.2.16 PMU Interrupt Disable Register
Register Name: PMU_IDR
Access Type: Write-only
Address: 0x1F
A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access.
•SHORT1:
0: no effect.
1: the overcurrent detection interrupt on BOOST/SEPIC1 is disabled.
•PG1:
0: no effect.
1: the power good interrupt of BOOST/SEPIC1 is disabled.
•PF1:
0: no effect.
1: the power fail interrupt of BOOST/SEPIC1 is disabled.
•PG2:
0: no effect.
1: the power good interrupt of BUCK2 is disabled.
•PF2:
0: no effect.
1: the power fail interrupt of BUCK2 is disabled.
76543210
– – PF2 PG2 – PF1 PG1 SHORT1
–– –––
38
6266A–PMAAC–08-Sep-08
AT73C224
6.2.17 PMU Interrupt Mask Register
Register Name: PMU_IMR
Access Type: Read-only
Address: 0x20
A minimum of 3 clock cycles of 15 kHz clock must be waited after any read operation before doing a new register access.
•SHORT1:
0: the overcurrent detection interrupt on BOOST/SEPIC1 is disabled.
1: the overcurrent detection interrupt on BOOST/SEPIC1 is enabled.
•PG1:
0: the power good interrupt of BOOST/SEPIC1 is disabled.
1: the power good interrupt of BOOST/SEPIC1 is enabled.
•PF1:
0: the power fail interrupt of BOOST/SEPIC1 is disabled.
1: the power fail interrupt of BOOST/SEPIC1 is enabled.
•PG2:
0: the power good interrupt of BUCK2 is disabled.
1: the power good interrupt of BUCK2 is enabled.
•PF2:
0: the power fail interrupt of BUCK2 is disabled.
1: the power fail interrupt of BUCK2 is enabled.
76543210
– – PF2 PG2 – PF1 PG1 SHORT1
00 000
39
6266A–PMAAC–08-Sep-08
AT73C224
6.3 Interrupt Registers
6.3.1 Interrupt Enable Register
Register Name: IRQ_EN
Access Type: Write-only
Address: 0x30
A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access.
•RTC:
Enables the RTC interrupt when written to 1.
Writing 0 has no effect.
•PB:
Enables the push-button interrupt when written to 1.
Writing 0 has no effect.
•PWR:
Enables the power failure interrupt when written to 1.
Writing 0 has no effect
• DC1:
Enables the BOOST/SEPIC1 interrupt when written to 1.
Writing 0 has no effect.
• DC2:
Enables the BUCK2 interrupt when written to 1.
Writing 0 has no effect.
• ALL:
Writing to 1 globally enables all the interrupt sources that had been previously enabled individually. The interrupt setting for
each source is restored.
Writing 0 has no effect.
76543210
ALL – DC2 DC1 – PWR PB RTC
––––––
40
6266A–PMAAC–08-Sep-08
AT73C224
6.3.2 Interrupt Disable Register
Register Name: IRQ_DIS
Access Type: Write-only
Address: 0x31
A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access.
•RTC:
Disables the RTC interrupt when written to 1.
Writing 0 has no effect.
•PB:
Disables the push-button interrupt when written to 1.
Writing 0 has no effect.
•PWR:
Disables the power failure interrupt when written to 1.
Writing 0 has no effect
• DC1:
Disables the BOOST/SEPIC1 interrupt when written to 1.
Writing 0 has no effect.
• DC2:
Disables the BUCK2 interrupt when written to 1.
Writing 0 has no effect.
• ALL:
Writing to 1 globally disables all the interrupt sources. The individual setting of each interrupt source is saved.
Writing 0 has no effect.
76543210
ALL – DC2 DC1 – PWR PB RTC
––––––
41
6266A–PMAAC–08-Sep-08
AT73C224
6.3.3 Interrupt Mask Register
Register Name: IRQ_MSK
Access Type: Read-only
Address: 0x32
This register summarizes the result of the successive interrupt enable/disable commands performed by writing into
IRQ_EN/IRQ_DIS.
•RTC:
0: the RTC interrupt is masked.
1: the RTC interrupt is unmasked.
•PB:
0: the push-button interrupt is masked.
1: the push-button interrupt is unmasked.
•PWR:
0: the power failure interrupt is masked.
1: the power failure interrupt is unmasked.
• DC1:
0: the BOOST/SEPIC1 interrupt is masked.
1: the BOOST/SEPIC1 interrupt is unmasked.
• DC2:
0: the BUCK2 interrupt is masked.
1: the BUCK2 interrupt is unmasked.
• ALL:
0: the interrupt sources are globally masked.
1: the interrupt sources are globally unmasked.
76543210
ALL – DC2 DC1 – PWR PB RTC
00000000
42
6266A–PMAAC–08-Sep-08
AT73C224
6.3.4 Interrupt Status Register
Register Name: IRQ_STA
Access Type: Read-only
Address: 0x33
A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access.
Reading IRQ de-asserts the ITB signal.
•RTC:
1: signals a pending interrupt request from the RTC.
•PB:
1: signals a pending interrupt request from the push-button.
•PWR:
1: signals a pending interrupt request from the power monitor.
• DC1:
1: signals a pending interrupt request from the BOOST/SEPIC1.
• DC2:
1: signals a pending interrupt request from the BUCK2.
76543210
– – DC2 DC1 – PWR PB RTC
00000000
43
6266A–PMAAC–08-Sep-08
AT73C224
6.4 RTC Registers
6.4.1 RTC Control Register
Register Name: RT_CR
Access Type: Read/Write
Address: 0x40
•UPDTIM:
Writing 1 requests the RTC to stop the time counter so that it can be safely updated. The time counter is actually stopped
only when ACKUPD is set in RTC_SR.
Writing 0 restarts the time counter.
• UPDCAL:
Writing 1 requests the RTC to stop the calendar counter so that it can be safely updated. The calendar counter is actually
stopped only when ACKUPD is set in RTC_SR.
Writing 0 restarts the calendar counter.
• TIMEVSEL:
Selects the type of event to cause TIMEV to change in RTC_SR.
• CALEVSEL:
Selects the type of event to cause CALEV to change in RTC_SR.
76543210
CALEVSEL TIMEVSEL – – UPDCAL UPDTIM
0000 00
00 minute change
01 hour change
10 every day at midnight
11 every day at noon
00 week change every
Monday
at time
00:00:00
01 month change every 1st of
each month
at time
00:00:00
10
11 year change every 1st of
January
at time
00:00:00
44
6266A–PMAAC–08-Sep-08
AT73C224
6.4.2 RTC Reset Register
Register Name: RT_RR
Access Type: Read/Write
Address: 0x41
RST:
RST = 0, Normal Operation
RST=1, Reset the RTC
6.4.3 RTC Mode Register
Register Name: RT_MR
Access Type: Read/Write
Address: 0x44
• HRMOD:
0: 24-hour mode.
1: 12-hour mode.
76543210
RST–––––––
0
76543210
–––––––HRMOD
0
45
6266A–PMAAC–08-Sep-08
AT73C224
The three Time writing registers are only writable concomitantly and must be written in the order as shown below:
1. RT_SEC
2. RT_MIN
3. RT_HOUR
6.4.4 Real-time Second Register
Register Name: RT_SEC
Access Type: Read/Write
Address: 0x48
• SEC:
The range is 0-59 encoded in Binary Coded Decimal (BCD). The lowest four bits encode the units, the higher bits encode
the tens.
This field must not be written unless the time counter has been stopped.
6.4.5 Real-time Minute Register
Register Name: RT_MIN
Access Type: Read/Write
Address: 0x49
•MIN
The range is 0-59 encoded in BCD. The lowest four bits encode the units, the higher bits encode the tens. This field must
not be written unless the time counter has been stopped.
6.4.6 Real-time Hour Register
Register Name: RT_HOUR
Access Type: Read/Write
Address: 0x4A
• HOUR:
Depending on bit AMPM, the range can be 1-12 or 0-23, encoded in BCD. The lowest four bits encode the units, the higher
bits encode the tens. This field must not be written unless the time counter has been stopped.
• AMPM:
This bit controls/reflects the AM/PM indicator in 12-hour mode.
0: AM.
1: PM.
76543210
–SEC
0000000
76543210
–MIN
0000000
76543210
–AMPM HOUR
0000000
46
6266A–PMAAC–08-Sep-08
AT73C224
The four Date writing registers are only writable concomitantly and must be written in the order as shown below:
1. RT_CENT
2. RT_YEAR
3. RT_MONTH
4. RT_DATE
6.4.7 Real-time Century Register
Register Name: RT_CENT
Access Type: Read/Write
Address: 0x4C
•CENT:
The range is 19 - 20, encoded in BCD. The lowest four bits encode the units, the higher bits encode the tens.
6.4.8 Real-time Year Register
Register Name: RT_YEAR
Access Type: Read/Write
Address: 0x4C
• YEAR:
The range is 1 - 12, encoded in BCD. The lowest four bits encode the units, the higher bits encode the tens.
6.4.9 Real-time Month Register
Register Name: RT_Month
Access Type: Read/Write
Address: 0x4E
•MONTH:
The range is 1 - 12, encoded in BCD. The lowest four bits encode the units, the higher bits encode the tens.
•DAY:
The range is 1-7 and represents the day of the week. The relationship between the coding of this field and the actual day of
the week, is user-defined. Especially, writing to this bit has no effect on the date counter.
76543210
– – CENT
011001
76543210
YEAR
10011000
76543210
DAY MONTH
10000001
47
6266A–PMAAC–08-Sep-08
AT73C224
6.4.10 Real-time Date Register
Register Name: RT_DATE
Access Type: Read/Write
Address: 0x4F
•DATE:
The range is 1 - 31, encoded in BCD and represents the day of the month. The lowest four bits encode the units, the higher
bits encode the tens.
76543210
DAY DATE
10011000
48
6266A–PMAAC–08-Sep-08
AT73C224
The three Time Alarm writing registers are only writable concomitantly and must be written in the order as shown below:
1. RT_SECA
2. RT_MINA
3. RT_HOURA
6.4.11 Real-time Second Alarm Register
Register Name: RT_SECA
Access Type: Read/Write
Address: 0x50
• SEC:
This field is the alarm field corresponding to the BCD-encoded second counter.
• SECEN
0: the second-matching alarm is disabled.
1: the second-matching alarm is enabled.
6.4.12 Real-time Minute Alarm Register
Register Name: RT_MINA
Access Type: Read/Write
Address: 0x51
•MIN:
This field is the alarm field corresponding to the BCD-encoded minute counter.
•MINEN
0: the minute-matching alarm is disabled.
1: the minute-matching alarm is enabled.
76543210
SECEN SEC
00000000
76543210
MINEN MIN
00000000
49
6266A–PMAAC–08-Sep-08
AT73C224
6.4.13 Real-time Hour Alarm Register
Register Name: RT_HOURA
Access Type: Read/Write
Address: 0x52
• HOUR:
This field is the alarm field corresponding to the BCD-encoded hour counter.
• AMPM:
This field is the alarm field corresponding to the BCD-encoded hour counter.
• HOUREN
0: the hour-matching alarm is disabled.
1: the hour-matching alarm is enabled.
76543210
HOUREN AMPM HOUR
00000000
50
6266A–PMAAC–08-Sep-08
AT73C224
The two Date Alarm writing registers are only writable concomitantly and must be written in the order as shown below:
1. RT_MONTHA
2. RT_DATEA
6.4.14 Real-time Month Alarm Register
Register Name: RT_MONTHA
Access Type: Read/Write
Address: 0x56
•MONTH:
This field is the alarm field corresponding to the BCD-encoded month counter.
•MTHEN
0: the month-matching alarm is disabled.
1: the month-matching alarm is enabled.
6.4.15 Real-time DATE Alarm Register
Register Name: RT_DATEA
Access Type: Read/Write
Address: 0x56
•DATE:
This field is the alarm field corresponding to the BCD-encoded day of the month counter.
• DATEEN:
0: the day of the month-matching alarm is disabled.
1: the day of the month-matching alarm is enabled.
76543210
MTHEN – – MONTH
0 00001
76543210
DATEEN – DATE
0 000001
51
6266A–PMAAC–08-Sep-08
AT73C224
6.4.16 RTC Status Register
Register Name: RTC_SR
Access Type: Read-only
Address: 0x58
• ACKUPD:
0: time and calendar registers should not be updated.
1: time and calendar can be updated safely (clock stopped).
•ALARM:
0: no alarm matching condition occurred.
1: an alarm matching condition occurred.
• SEC:
0: no second event has occurred since last clear.
1: at least one second event occurred since last clear.
•TIMEV:
0: no time event has occurred since last clear.
1: at least one time event occurred since last clear.
The time event is selected by the TIMEVSEL field in RTC_CR and can be any of the following events: minute change, hour
change, noon, midnight (day change).
• CALEV:
0: no calendar event occurred since last clear.
1: at least one calendar event occurred since last clear.
The calendar event is selected in the CALEVSEL field in RTC_CR and can be any of the following events: week change,
month change, or year change.
76543210
– – – CALEV TIMEV SEC ALARM ACKUPD
00000
52
6266A–PMAAC–08-Sep-08
AT73C224
6.4.17 RTC Status Clear Command Register
Register Name: RTC_SCCR
Access Type: Write-only
Address: 0x5C
• ACKCLR:
0: no effect.
1: clears the ACKUPD bit in RTC_SR.
• ALCLR:
0: no effect.
1: clears the ALARM bit RTC_SR.
• SECCLR:
0: no effect.
1: clears the SEC bit RTC_SR.
• TIMCLR:
0: no effect.
1: clears the TIMEV bit RTC_SR.
• CALCR:
0: no effect.
1: clears the CALEV bit RTC_SR.
76543210
– – – CALCLR TIMCLR SECCLR ALRCLR ACKCLR
00000
53
6266A–PMAAC–08-Sep-08
AT73C224
6.4.18 RTC Interrupt Enable Register
Register Name: RTC_IER
Access Type: Write-only
Address: 0x60
• ACKEN:
0: no effect.
1: the acknowledge for update interrupt is enabled.
•ALREN:
0: no effect.
1: the alarm interrupt is enabled.
• SECEN:
0: no effect.
1: the second periodic interrupt is enabled.
•TIMEN:
0: no effect.
1: the selected time event interrupt is enabled.
• CALEN:
0: no effect.
1: the selected calendar event interrupt is enabled.
76543210
– – – CALEN TIMEN SECEN ALREN ACKEN
00000
54
6266A–PMAAC–08-Sep-08
AT73C224
6.4.19 RTC Interrupt Disable Register
Register Name: RTC_IDR
Access Type: Write-only
Address: 0x64
• ACKDIS:
0: no effect.
1: the acknowledge for update interrupt is disabled.
•ALRDIS:
0: no effect.
1: the alarm interrupt is disabled.
• SECDIS:
0: no effect.
1: the second periodic interrupt is disabled.
•TIMDIS:
0: no effect.
1: the selected time event interrupt is disabled.
• CALDIS:
0: no effect.
1: the selected calendar event interrupt is disabled.
76543210
– – – CALDIS TIMDIS SECDIS ALRDIS ACKDIS
00000
55
6266A–PMAAC–08-Sep-08
AT73C224
6.4.20 RTC Interrupt Mask Register
Register Name: RTC_IMR
Access Type: Read-only
Address: 0x68
• ACK:
0: the acknowledge for update interrupt is disabled.
1: the acknowledge for update interrupt is enabled.
•ALR:
0: the alarm interrupt is disabled.
1: the alarm interrupt is enabled.
• SEC:
0: the second periodic interrupt is disabled.
1: the second periodic interrupt is enabled.
•TIM:
0: the selected time event interrupt is disabled.
1: the selected time event interrupt is enabled.
• CAL:
0: the selected calendar event interrupt is disabled.
1: the selected calendar event interrupt is enabled.
76543210
–––CALTIMSECALRACK
00000
56
6266A–PMAAC–08-Sep-08
AT73C224
6.4.21 RTC Valid Entry Register
Register Name: RTC_VER
Access Type: Read-only
Address: 0x6C
•NVTIM:
0: no invalid data has been detected in the time registers.
1: invalid data has been detected.
•NVCAL:
0: no invalid data has been detected in the calendar registers.
1: invalid data has been detected.
•NVTIMA:
0: no invalid data has been detected in the time alarm registers.
1: invalid data has been detected.
• NVCALA:
0: no invalid data has been detected in the calendar alarm registers.
1: invalid data has been detected.
76543210
––––NVCALANVTIMANVCALNVTIM
57
6266A–PMAAC–08-Sep-08
AT73C224
7. Electrical Characteristics
With external components as listed in Table 4-1, Ta = -40°C to 85°C typical values are at Ta =
25°C (unless otherwise specified).
7.1 Absolute Maximum Ratings
7.2 Recommended Operating Conditions
Table 7-1. Absolute Maximum Ratings
Operating Temperature (Industrial).............-40°C to + 85°C*NOTICE: Stresses beyond those listed under “Absolute Maximum
Ratings” may cause permanent damage to the device.
This is a stress rating only and functional operation of the
device at these or other conditions beyond those indi-
cated in the operational sections of this specification is
not implied. Exposure to absolute maximum rating condi-
tions for extended periods may affect device reliability.
Storage Temperature..................................-55°C to + 150°C
Power Supply Input........................................-0.3V to + 5.5V
I/O Input.......................................................... -0.3V to + 5.5V
ESD (all pins)-..................................................................2 KV
Table 7-2. Recommended Operating Conditions
Parameter Condition Min Max Unit
Operating Temperature -40 85 °C
Power Supply Input 2.8 5.25 V
58
6266A–PMAAC–08-Sep-08
AT73C224
7.3 Digital I/Os
Digital I/Os are supplied by VDDIO. VDDIO is an input and must be externally connected.
.
VDDIO referred pins EN, D1, D3, D4: CMOS inputs. Only VIH and VIL parameters are
applicable.
VDDIO referred pins POK: CMOS output. Only VOL, VOH parameters are applicable.
VDDIO referred pin ITB, D2: CMOS BiDir. All parameters applicable.
7.4 Current Consumption Versus Modes
Table 7-3. VDDIO Referred Digital I/Os
Symbol Parameter Conditions Min Typ Max Unit
VDDIO Operating Supply Voltage 1.75 3.6 5.25 V
VIL Input Low Level Voltage -0.3 0.3x
VDDIO V
VIH Input High Level Voltage 0.7x
VDDIO
VDDIO
+ 0.3 V
VOL Output Low Level Voltage 0.75x
VDDIO V
VOH Output high Level Voltage 0.25x
VDDIO V
Io Output Current 8mA
Rp Pull-Up or Pull Down
resistance when applicable 90 120 150 kΩ
Table 7-4. Quiescent Current in Different Operating Modes
Status Conditions Battery Current
Typ Max
Off No battery is present N/A N/A
Backup mode
No Main Battery is present
Backup battery present (and charged):
. Running:
RTC (dig + oscillator 32 kHz) - supply: vbackup pin 1 µA 2 µA
Stand by
Main Battery plugged in and higher than 2.8V
Backup battery present (and charged)
. Power supplies off (BOOST1, BUCK2, LDO3, LDO4)
. Running:
RTC, LDO_RTC - supply: vbat_ldortc
POR, LPBG, VMON - supply: vdd0 pin
4µA
9µA
7µA
17µA
59
6266A–PMAAC–08-Sep-08
AT73C224
7.5 BOOST1: Step-up Converter
Note: 1. Before the BOOST is turned on, it is recommended to establish low current limitation (typic: 1 Amp) to avoid current peak on
main supply.
Table 7-5. BOOST1 Electrical Characteristics
Symbol Parameter Conditions Min Typ Max Unit
VDD1 Operating Supply Voltage 2.8 3.6 5.25 V
Fs Converter Frequency 400 900 1400 kHz
IOLoad Current 1A
VO1 Output Voltage BST_VOLT register (@12) - Step 100 mV
VDD1 < VO1 3.2 5.2 V
Error Output voltage precision Iload > 100 mA -10 -10 %
Isc Shutdown Current BST_CLR register (@10); EN = 0 1 µA
ILIM Current Limitation BST_CFG register (@11) 0.5 7(1) A
η2.8_3.3_1A Efficiency at VDD1 = 2.8 V IO = 1 A, VDD1 = 2.8V, VO1 = 3.3V 90 %
h3.6_5.2_1A Efficiency at VDD1 = 3.6 V IO = 1 A, VDD1 = 3.3V, VO1 = 5.2V 85 %
tSTART Start-up Time No load 200 µs
∆VO1_5.2V Ripple Voltage peak-to-peak, IO = 1 A, VO1 = 5.2V
Bandwidth = 20 MHz 200 mV
∆VO1_5.2V Static Line Regulation VDD1: 2.8 to 4.2V - IO = 1 A - VO1 = 5.2V 200 mV
∆VO1_5.2V Static Load Regulation VDD1: 3.6V - IO: 100 mA to 900 mA -
VO1 = 5.2V 50 mV
60
6266A–PMAAC–08-Sep-08
AT73C224
7.5.1 BOOST1: Typical Characteristics
Figure 7-1. Efficiency BOOST1 - VO1 = 5V -
Iload (A)
VDD1 = 3V
VDD1 = 2.8V
VDD1 = 4.2V
VDD1 = 3.6V
60
65
70
75
80
85
90
95
100
0.01 0.1 1
61
6266A–PMAAC–08-Sep-08
AT73C224
Figure 7-2. Load Regulation BOOST1 - VO1 = 5V -
The BOOST1 cell can be implemented using proper external components. (See Figure 4-3
“Application Schematic 3: BOOST in SEPIC Configuration (BUCK/BOOST)”.)
Iload (A)
VDD1 = 3V
VDD1 = 2.8V
VDD1 = 4.2V
VDD1 = 3.6V
5.02
5.04
5.06
5.08
5.1
5.12
5.14
5.16
5.18
5.2
5.22
5.24
5.26
5.28
5.3
5.32
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
62
6266A–PMAAC–08-Sep-08
AT73C224
7.6 BUCK2: Step-down Converter
Note: 1. for device commanded in Dynamic Mode only. For devices commanded in Static Mode, the minimum voltage is 1.8V.
The BUCK2 is a Pulse Width Modulator (PWM) / Pulse-Skipping (PSK) synchronous regulator
that can be used to provide an accurate 0.9V to 3.4V programmable output voltage at 500 mA of
maximum load current.
Integrated current sensing is used to sense the DC/DC converter load current used for the over-
current circuit protection and for the PWM / PSK mode selector.
By default, the BUCK2 is in Automatic Mode: according to the load current value, the regulator is
either in Pulse-Skipping mode (light load) or in PWM mode (high load). In dynamic mode, the
user can select PWM or PSK mode, using the bits 4 and 5 of the BCK_CFG register (see Sec-
tion 6 Register Tables).
Note that the Automatic mode should not be used for output voltages below 1.8V.
Table 7-6. BUCK2 Electrical Characteristics
Symbol Parameter Conditions Min Typ Max Unit
VDD2 Operating Supply Voltage 2.8 3.6 5.25 V
Fs Converter Frequency PWM mode 400 900 1400 kHz
ILOAD Load Current 0.5 A
VO2 Output Voltage BCK_VOLT register (@15) - Step 100mV
VDD2 > (VO2 + 0.2V) 0.9(1) 3.4 V
Error Output Voltage Precision -10 10 %
ISC Shutdown Current BCK_CTROL register (@13), EN = 0 1 6 µA
ISTB Stand-by Current BCK_CTROL register (@13), EN = 1, clock not present 20 50 µA
IMAX Short Circuit Current BCK_CFG register (@14) 1 2 A
IPWM-PSK
PWM – Pulse SKipping
Current Threshold Automatic mode- VDD2 = 3.6V- VO2 = 1.8V 70 mA
∆v Ripple Voltage PWM mode 10 mV
TRRise Time Bandgap already started, slow-start power up selected 1 ms
∆VDC Static Line Regulation ILOAD = 500 mA, VDD2 from 2.8V to 5V
PWM mode 80 mV
∆VDC Static Load Regulation 1 mA <iload<500 mA,
PWM mode 40 mV
63
6266A–PMAAC–08-Sep-08
AT73C224
7.6.1 BUCK2: Typical Characteristics
Figure 7-3. Efficiency Manual/Automatic Modes
Efficiency VO2 = 1.8V - Manual Mode: PSK/PWM Efficiency VO2 = 3.3V - Manual Mode: PSK/PWM
Efficiency VO2 = 1.2V - Manual Mode: PSK/PWM
Efficiency VO2 = 0.9V - Manual Mode: PSK/PWM
Efficiency (%)
Iload (A)
Efficiency (%)
Efficiency (%)
Efficiency (%)
Iload (A)
Iload (A) Iload (A)
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
0.001 0.01 0.1 1
VDD2 = 3.6V
VDD2 = 2.8V
VDD2 = 4.2V
VDD2 = 5V
VDD2 = 3.6V
VDD2 = 2.8V
VDD2 = 4.2V
VDD2 = 5V
VDD2 = 5V
VDD2 = 4.2V
VDD2 = 4.2V
VDD2 = 5V
VDD2 = 3.6V
VDD2 = 2.8V
VDD2 = 4.2V
VDD2 = 5V
VDD2 = 3.6V
VDD2 = 2.8V
VDD2 = 4.2V
VDD2 = 5V
VDD2 = 3.6V
VDD2 = 2.8V
VDD2 = 4.2V
VDD2 = 5V
VDD2 = 3.6V
VDD2 = 2.8V
VDD2 = 4.2V
VDD2 = 5V
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
0.001 0.01 0.1 1
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
0.001 0.01 0.1 1
Efficiency VO2 = 3.3V - Automatic Mode
Iload (A)
Efficiency (%)
VDD2 = 4.2V
VDD2 = 5V
60
65
70
75
80
85
90
95
100
0.001 0.01 0.1 1
Efficiency VO2 = 1.8V - Automatic Mode
Iload (A)
Efficiency (%)
VDD2 = 3.6V
VDD2 = 2.8V
VDD2 = 4.2V
VDD2 = 5V
45
50
55
60
65
70
75
80
85
90
95
100
0.001 0.01 0.1 1
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
0.001 0.01 0.1 1
PWM
PSK
PWM
PSK
PWM
PSK
PWM
PSK
64
6266A–PMAAC–08-Sep-08
AT73C224
7.6.2 BUCK2: Load Regulation of VO2
Figure 7-4. Load Regulation
0.85
0.86
0.87
0.88
0.89
0.9
0.91
0.92
0.93
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5
1.15
1.16
1.17
1.18
1.19
1.2
1.21
1.22
1.23
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5
1.72
1.74
1.76
1.78
1.8
1.82
1.84
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5
3.22
3.23
3.24
3.25
3.26
3.27
3.28
3.29
3.3
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5
Load Regulation: VO2 = 0.9V (PWM mode) Load Regulation: VO2 = 1.2V (PWM mode)
Load Regulation: VO2 = 1.8V (PWM Mode) Load Regulation: VO2 = 3.3V (PWM mode)
I load (A) I load (A)
I load (A) I load (A)
VO2 (V) VO2 (V)
VO2 (V)
VO2 (V)
VDD2 = 5V
VDD2 = 4.2V
VDD2 = 3.6V
VDD2 = 2.8V
VDD2 = 2.8V
VDD2 = 3.6V
VDD2 = 4.2V
VDD2 = 5.5V
VDD2 = 2.8V
VDD2 = 3.6V
VDD2 = 4.2V
VDD2 = 5.5V
VDD2 = 5.5V
VDD2 = 4.2V
65
6266A–PMAAC–08-Sep-08
AT73C224
7.7 LDO3 & LDO4
LDO3 and LDO4 are low-drop-out voltage regulators that can provide a 1.3V, 1.5V to 1.8V (step
100 mV), 2.5V to 2.8V (100 mV step) or 3.3V output voltage.
Two kinds of applications are defined: “RF” mode (high PSRR and low noise) with 100 mA max-
imum load and “Smoother” mode with 200 mA maximum load.
By default, the LDOs are configured in RF mode. If the load is higher than 100 mA, the user
should pass into Smoother mode (see the register tables in Section 6.2.8 ”LDO3 Configuration
Register” and Section 6.2.11 ”LDO4 Configuration Register”).
An external 2.2 µF ceramic capacitor is needed for the stability of each LDO.
Table 7-7. LDO3 and LDO4 Electrical Characteristics
Symbol Parameter Conditions Min Typ Max Unit
VDD3&4 Operating Supply Voltage 2.8 3.6 5.25 V
ILOAD_S Smoother Load current In Smoother mode 0 200 mA
ILOAD_RF RF Load current In RF mode 0 100 mA
VO3,
VO4 Output Voltage
Selection in LDO3_VOLT @ 18 and
LDO4_VOLT @ 1B
VDD3 > VO3 + 200mV
VDD4 > VO4 + 200mV
1.3 3.3 V
∆VoAccuracy ILOAD=10mA -8 8 %
ISC Shutdown Current GND output
(LDO3_CFG@17 and LDO4_CFG@1A) 1µA
IQQ Quiescent Current No load 20 µA
tRRise Time 100 µs
∆VDC Line Regulation Static 2.8V < VDD3 < 5.25V, full load 10 mV
∆VDC Load Regulation Static 10 mA <ILOAD <100 mA 10 5 mV
nOutput Noise In RF mode
Bandwidth: [22 - 80kHz] 1.5 µVrms
PSRR Power Supply Rejection Ratio
In RF mode:
ILOAD=100mA, 100 Hz
ILOAD=100mA, 1kHz
ILOAD=100mA, 10kHz
ILOAD=100mA, 100kHz
70
65
55
45
dB
dB
dB
dB
66
6266A–PMAAC–08-Sep-08
AT73C224
7.7.1 LDO3 and LDO4: Typical Characteristics
Figure 7-5. LDO Load Regulation
Shown below is VO3 Ripple (same as VO4) in response to a load current pulse from 10 mA to
200 mA.
Channel 2: VO3 = 1.8V and VO3 = 3.3V (50mV/div)
Channel 1: Iload = 10 mA - 200 mA (100 mA/div)
Load regulation VO3 = 3.3V
Iload (A)
VO3 (V)
Iload (A)
Load regulation VO3 = 1.8V
VDD3 = 5V
VDD3 = 4.2V
VDD3 = 3.6V
VDD3 = 3V
VDD3 = 2.8V
VDD3 = 5V
VDD3 = 4.2V
VDD3 = 3.6V
3.264
3.265
3.266
3.267
3.268
3.269
3.27
3.271
3.272
3.273
3.274
3.275
3.276
0 0.03 0.06 0.09 0.12 0.15 0.18 0.21 0.24 0.27 0.3
1.761
1.762
1.763
1.764
1.765
1.766
1.767
1.768
1.769
1.77
1.771
0 0.03 0.06 0.09 0.12 0.15 0.18 0.21 0.24 0.27 0.3
VO3 (V)
67
6266A–PMAAC–08-Sep-08
AT73C224
7.8 Real-time Clock (RTC)
The Real-time Clock architecture is shown in Figure 7-6 and is comprised of the following
blocks: 2.6V LDO_RTC voltage regulator with backup switch, RTC oscillator and RTC block.
7.8.1 Block Diagram
Figure 7-6. RTC Block Diagram
The LDO_RTC is used to charge the backup battery at 2.6V. When the main battery is plugged
in, the LDO is enabled and the backup switch is closed, thus charging the battery. If the
VBACKUP initial value is lower than the minimum backup voltage admissible (1.8V typical), an
active low reset is generated on reset signal.
The C11 capacitor is used for LDO compensation while the R2 resistor limits the charge current
for the backup battery.
The RTC oscillator is suited to work with a 32.768 kHz crystal oscillator and generates the
32.768 kHz clock for the RTC. The RTC block provides seconds, minutes, hours, days, date,
month, and year information. RTC time data is stored into a register that can be accessed via
the AT73C224-x device serial interface.
LDO
RTC
2.6V
RTC
OSC
RTC
Recharchable
Backup
Battery 2.5V
(NBL type)
RTC
Clock X1
32.768 kHz
crystal
VBACKUP
XIN
XOUT
VDD0 < 2.8V
switch open
LDO_RTC off
R2
C11
D0 to D4
Serial
Interface
VBAT_LDORTC
AT73C224-xAT73C224-x VDD0
VMON
68
6266A–PMAAC–08-Sep-08
AT73C224
7.8.2 LDO RTC
The LDO_Backup is a low drop out voltage regulator that is used to charge a 2.5V RTC
rechargeable backup battery (type NBL621). The max load current is 2 mA. An external 1 µF
ceramic capacitor (C11) is needed for compensation.
7.8.3 RTC Oscillator
The RTC Oscillator is a low-frequency, 2-Pad, Pierce-type Xtal oscillator, optimized for 32.768
kHz crystal. For operation with 6 pF load capacitance crystals, no external components are
needed on “xin” and “xout”. It may be necessary to add external capacitors on “xin” and “xout” to
ground in special cases, for example, to exactly set the frequency or for crystals with a load
capacitance superior to 6 pF. The “clock” output is low during standby. “xin” and “xout” must not
be used to drive other circuitry.
Table 7-8. LDO RTC Electrical Characteristics
Symbol Parameter Conditions Min Typ Max Unit
VBAT_LDORTC Operating Supply Voltage 2.8 5.25 V
VBACKUP Output Voltage Vbat_ldortc present 2.55 2.6 2.65 V
IOUT Load Current Dc load current 2 mA
IQQ Battery Quiescent Current en = 1 3 5 µA
IBKQQ Backup Battery Quiescent
Current en = 0 200 300 nA
ISC Shutdown Current 1µA
TSStart-up Time 1ms
VTH Reset Threshold reset is active low 1.8 V
Table 7-9. RTC Oscillator Electrical Characteristics
Symbol Parameter Conditions Min Typ Max Unit
VBACKUP Supply voltage 1.75 2.65
FCK Operating frequency 32.768 kHz
Duty Duty cycle 40 50 60 %
Ton Startup time 900 ms
VSIN Level sinus wave on xin RS = 50 KΩ160 260 360 mVpp
DRV Drive level RS = 50 KΩ0.1 µW
I Current dissipation OFF 5 nA
ON 0.8 2 µA
ACC Accuracy T = 25 °C 3 mn/month
RSEquivalent series resistance Crystal @ 32.768kHz 50 kΩ
CMT Motional capacitance Crystal @ 32.768kHz 1 3 fF
CSHUNT Shunt capacitance Crystal @ 32.768kHz 0.6 2 pF
CLOAD Load capacitance Crystal @ 32.768kHz 6 12.5 pF
69
6266A–PMAAC–08-Sep-08
AT73C224
7.9 VINT
One external capacitor (47 0nF) is necessary on VINT pin for functionality of the internal LDO
supply. This voltage should not be used by the user.
70
6266A–PMAAC–08-Sep-08
AT73C224
8. Package Drawing
Figure 8-1. QFN 32-lead Package Drawing (all dimensions in millimeters)
R-QFN032_H
71
6266A–PMAAC–08-Sep-08
AT73C224
9. Revision History
Doc. Rev. Comments
Change
Request
Ref.
6266A First issue.
72
6266A–PMAAC–08-Sep-08
AT73C224
i
6266A–PMAAC–08-Sep-08
AT73C224
Table of Contents
Features ..................................................................................................... 1
1 Description ............................................................................................... 1
2 Block Diagram .......................................................................................... 3
3 Pinout ........................................................................................................ 4
4 Application examples .............................................................................. 5
5 Detailed Description ................................................................................ 9
5.1 Core ...................................................................................................................9
5.2 Automatic Start-up Sequences and Shut-down ...............................................10
5.3 Digital Control and Protocol .............................................................................13
6 Register Tables ...................................................................................... 20
6.1 System Registers ............................................................................................20
6.2 PMU Registers ................................................................................................23
6.3 Interrupt Registers ...........................................................................................39
6.4 RTC Registers .................................................................................................43
7 Electrical Characteristics ...................................................................... 57
7.1 Absolute Maximum Ratings .............................................................................57
7.2 Recommended Operating Conditions .............................................................57
7.3 Digital I/Os .......................................................................................................58
7.4 Current Consumption Versus Modes ..............................................................58
7.5 BOOST1: Step-up Converter ...........................................................................59
7.6 BUCK2: Step-down Converter .........................................................................62
7.7 LDO3 & LDO4 .................................................................................................65
7.8 Real-time Clock (RTC) ....................................................................................67
7.9 VINT ................................................................................................................69
8 Package Drawing ................................................................................... 70
9 Revision History ..................................................................................... 71
Table of Contents....................................................................................... i
ii
6266A–PMAAC–08-Sep-08
AT73C224
6266A–PMAAC–08-Sep-08
Headquarters International
Atmel Corporation
2325 Orchard Parkway
San Jose, CA 95131
USA
Tel: 1(408) 441-0311
Fax: 1(408) 487-2600
Atmel Asia
Room 1219
Chinachem Golden Plaza
77 Mody Road Tsimshatsui
East Kowloon
Hong Kong
Tel: (852) 2721-9778
Fax: (852) 2722-1369
Atmel Europe
Le Krebs
8, Rue Jean-Pierre Timbaud
BP 309
78054 Saint-Quentin-en-
Yvelines Cedex
France
Tel: (33) 1-30-60-70-00
Fax: (33) 1-30-60-71-11
Atmel Japan
9F, Tonetsu Shinkawa Bldg.
1-24-8 Shinkawa
Chuo-ku, Tokyo 104-0033
Japan
Tel: (81) 3-3523-3551
Fax: (81) 3-3523-7581
Product Contact
Web Site
www.atmel.com
www.atmel.com/PowerManagement
Technical Support
pmaac@atmel.com
Atmel techincal support
Sales Contacts
www.atmel.com/contacts/
Literature Requests
www.atmel.com/literature
Disclaimer: The information in this document is provided in connection with Atmel products. No license, express or implied, by estoppel or otherwise, to any
intellectual property right is granted by this document or in connection with the sale of Atmel products. EXCEPT AS SET FORTH IN ATMEL’S TERMS AND CONDI-
TIONS OF SALE LOCATED ON ATMEL’S WEB SITE, ATMEL ASSUMES NO LIABILITY WHATSOEVER AND DISCLAIMS ANY EXPRESS, IMPLIED OR STATUTORY
WARRANTY RELATING TO ITS PRODUCTS INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
PURPOSE, OR NON-INFRINGEMENT. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE, SPECIAL OR INCIDEN-
TAL DAMAGES (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS OF PROFITS, BUSINESS INTERRUPTION, OR LOSS OF INFORMATION) ARISING OUT
OF THE USE OR INABILITY TO USE THIS DOCUMENT, EVEN IF ATMEL HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. Atmel makes no
representations or warranties with respect to the accuracy or completeness of the contents of this document and reserves the right to make changes to specifica-
tions and product descriptions at any time without notice. Atmel does not make any commitment to update the information contained herein. Unless specifically pro-
vided otherwise, Atmel products are not suitable for, and shall not be used in, automotive applications. Atmel’s products are not intended, authorized, or warranted
for use as components in applications intended to support or sustain life.
© 2008 Atmel Corporation. All rights reserved. Atmel®, Atmel logo and combinations thereof, and others are registered trademarks or trade-
marks of Atmel Corporation or its subsidiaries. Other terms and product names may be trademarks of others.
