Requirements
AT91CAP9-STK Starter Kit User Guide
2-25
6351B–CAP–27-Jun-08
2.4.1.11 F11: Battery Charger
An Atmel AT73C205 stand alone battery charger is implemented on the board.
It manages the charge of an external Li-Ion battery plugs on the EI1 interface, from 5V AC/DC sector
adapter or VBUS USB Device external power source.
The battery charger is controlled by the AT91CAP9 TWI bus.
Two LEDs (yellow and green) indicate the charge status.
The implementation of the AT73C205 battery charger is shown below.
2.4.1.12 F12: RTC and Backup
2.4.1.12.1Backup
The first AT73C224 PMC provides a 3V VBACKUP power supply on its VBK power pin, from non-man-
aged VIN_PMC supply on it's VDDRTC power in.
This VBACKUP power supply recharges a manganese-lithium rechargeable coin battery in the EI12
interface. It also supplies the AT73C239 chip on it's VBAT power pin, which generates (VO4 output)
1.2V_SAVE to supply the VDDBU AT91CAP9 power supply.
When no external power supplies are applied on the board, the AT73C239 is only supplied by the man-
ganese-lithium rechargeable coin battery to maintain the VDDBU AT91CAP9 power supply
2.4.1.12.2RTC
The first AT73C224 PMC described above integrates an RTC module with an external 32,768 kHz
quartz connection. (
See “First AT73C224” on page 2-23.
The RTC module is powered by a non-managed VIN_PMC source on it's VDDRTC power pin. When no
external power supplies are applied on the board, the RTC module is powered on it's VBK power pin by
the manganese-lithium rechargeable coin battery, VBACKUP supply.
CHARGER_IRQ
U1
ACDC
1
CSB/BATTYPE
15
SCLK/IUSBSET
14
USB
2
BAT
3
BATS
4
ADCAUX
10
TS
9
GND
5
DIN/ISET1
12
EN
11
ITB
16
LED2
7
MAXS
8
LED1
6
DOUT/ISET2
13
GNDPAD
17
TP1
NC
VBAT
D1
YELLOW
2
1
D2
GREEN
2
1
BAT_TS
+
C6
10UF_16V
1
2
C5
10uF_1210
1
2
C4
100nF
1
2
5VDC_SECTOR
+
C3
10UF_16V
1
2
C1
10uF_1210
1
2
R1
1K
C2
100nF
1
2
R2
1K
5VDC_SECTOR
C7
10uF_1210
1
2
C8
1nF
1
2
MAXS
J4
HE14_3PTS
1
3
2
BATTERY CHARGER
TW CK
C9
10uF_1210
1
2
R172
0R
3V3
R173
0R
C282
10nF
1
2
R174
0R
TW D
VBUS
R3
10K
3V3