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
•
•
•
•
•
•
•
•
•
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
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.
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.
Part Number
AT73C224-x device series
Automatic Start-up Sequence
Management Mode
Order of power-on and output default values.
1 - BUCK2= 1.8V
2 - LDO4 = 2.8V
3 - LDO3 = 2.7V
1 - BUCK2 = 1.2V
2 - LDO4 = 1.8V
3 - LDO3 = 1.8V
1 - LDO4 = 2.8V
2 - BUCK2 = 1.8V
3 - LDO3 = 2.7V
1 - LDO4 = 1.8V
2 - BUCK2 = 1.2V
3 - LDO3 = 1.8V
1 - BOOST11 = 5.2V
2 - LDO4 = 3.3V
3 - LDO3 = 3V
1 - BUCK2 = 1.8V
2 - LDO4 = 2.8V
3 - LDO3 = 2.7V
1 - LDO4 = 2.8V
2 - BUCK2= 1.8V
3- LDO3 = 2.7V
1 - BOOST1 = 5.2V
2 - LDO4 = 3.3V
3 - LDO3 = 3V
Dynamic
Comments
AT73C224-A
BOOST1 can be activated after Start-up
sequence by a user command.
AT73C224-B
Dynamic
BOOST1 can be activated after Start-up
sequence by a user command.
AT73C224-C
Dynamic
BOOST1 can be activated after Start-up
sequence by a user command.
AT73C224-D
Dynamic
BOOST1 can be activated after Start-up
sequence by a user command.
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.)
Same as AT73C224-A.
AT73C224-E
Dynamic
AT73C224-F
Static
AT73C224-G
Static
Same as AT73C224-C.
AT73C224-H
Static
Same as AT73C224-E.
2
AT73C224
6266A–PMAAC–08-Sep-08
3. Pinout
Table 3-1.
Pin Name
VO3
VDD3
GNDANA
VCAPP
VINT
VDD0
VCAPN
VBG
VDD2
VBAT_LDORTC
VO2
EN
D4
POK
ITB/RDY
SW2
GND2
VO1
DH1
DL1
VSENSE1
VDD1
VDD4
VO4
VDDIO
D1
D2
D3
CK32
XOUT
XIN
VBACKUP
GND/AVSS
AT73C224 Pinout
I/O
O
PS
PS
I/O
PS
PS
I/O
O
PS
PS
I
I
I
O
I/O
O
PS
I
O
O
I
PS
PS
O
PS
I
I/O
I
O
I/O
I/O
O
PS
Pin #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
Type
Analog
Power
Ground
Analog
Power
Analog
Analog
Analog
Power
Power
Analog
Digital
Digital
Digital
Digital
Analog
Ground
Analog
Analog
Analog
Analog
Power
Power
Analog
Digital
supply
Digital
Digital
Digital
Digital
Analog
Analog
Analog
Ground
Function
LDO3 output voltage
LDO3 supply voltage
Analog ground
Not connected
Output of the internal LDO
Supply of the internal LDO
Not connected
Bandgap reference voltage
BUCK2 supply voltage
LDO_RTC Supply voltage
BUCK2 output voltage
Enable signal
Digital interface
Power Ok: indicates when start-up is completed
User Interrupt, GPIO and Shutdown control
BUCK2 inductor (NMOS switcher output)
BUCK2 ground
BOOST1 output voltage
Not connected
BOOST1 NMOS control signal
BOOST1 current limitation sense voltage
BOOST1 supply voltage
LDO4 supply voltage
LDO4 output voltage
Supply voltage for Digital I/O
Digital interface
Digital interface
Digital interface
32 kHz RTC output clock
RTC crystal oscillator output
RTC crystal oscillator input
Backup Battery and RTC supply
Main G
ND
and AV
SS
ground
die paddle connected to ground
(mandatory)
open drain
open drain
open drain
Ext. 2.2 µF capacitor (mandatory)
Must be connected to the main
battery
Internal 100 KΩ pull up
Internal 100 KΩ pull up
Internal 100 KΩ pull up
Must be connected to the main
battery (mandatory)
Should not be resistively loaded
Ext. 470 nF capacitor (mandatory)
Must be connected to the main
battery (mandatory)
Comments
Ext. 2.2 µF capacitor (mandatory)
4
AT73C224
6266A–PMAAC–08-Sep-08
AT73C224
4. Application examples
Figure 4-1.
Application Schematic 1: Microcontroller with 5V VBUS for 2 USB Host Transceivers
LDO3 = 2.7V
R2
Rechargeable
Backup
Battery
(NBL type)
X1
C11
32
CK32
VBACKUP
XOUT
XIN
uP uP uP
D1
VDDIO
D3
D2
C12
C4
V
BAT
C9
(AUX ADC, PLL)
LDO4 = 2.8V
VO4
VDD4
VDD1
R1
D1
L1
VO1
C1
V
BAT
C6
VDDIO
1
V
BAT
C3
C8
nc
C14
C5
nc
C10
V
BAT
VO3
VDD3
GNDANA
VCAPP
VINT
VDD0
VCAPN
VBG
VDD2
AT73C224-A
VBAT_LDORTC
VSENSE1
DL1
DH1
VO1
ITB/RDY
GND2
SW2
nc
Q1
Microcontroller
VO2
POK
EN
D4
BOOST1 = 5V
(VBUS USB)
GND/AVSS
Die
Paddle
USB HOST
transceiver
V
BAT
V
BAT
C7
V
BAT
C13
uP uP uP
Pushbutton
L2
USB HOST
transceiver
SCK / TWCK
SDI /Adrress
SDO / TWD
POK ITB/RDY D1
ITB/RDY
C2
C16
RST
D2 D3 D4
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.
SCS / GND
3V
to
4.2V
Li-Ion
Battery
VO2
BUCK2 = 1.8V
SPI / TWI
VCORE
5
6266A–PMAAC–08-Sep-08
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