Requirements
2-24
AT91CAP9-STK Starter Kit User Guide
6351B–CAP–27-Jun-08
LTC3412: 1.2V_FPGA/1A
2.4.1.10.2Low-power Mode
The power supply of this 3 PMC (VIN_PMC_SHDN) is managed by the AT91CAP9 SHDN signal (power
by VDDBU. (
See “F12: RTC and Backup” on page 2-25.
)
When AT91CAP9 commands low power mode, it drives it's SDHN pin low and so switches off the 3 PMC
power supply. The implementation of the switch is shown below:
No external pull-up is required on the SHDN signal (even at start-up).
J58
C195
22uF_1210
1
2
C198
2200pF
1
2
C199
220p F 100V
1
2
1V2_FPGA
C203
2200pF
NC
1
2
R163
10K
C202
2200pF
1
2
R158
100K
FPGA_POK
C201
1UF_16V
1
2
R169
0R
R165
1K
NC
R159
0R
VIN_PMC_SHDN
R166
6K81
R161
12K4
R160
1K
L20
1UH_1A8
1
2
C197
220p F 100V
1
2
C204
220p F 100V
1
2
U18
LTC3412EFE
SV
IN
1
PGN
D
12
SG
N
D
8
PV
IN
16
PV
IN
9
SW14
14
SW15
15
SW10
10
SW11
11
PGN
D
13
RT
5
VFB
4
SYNC/MODE
6
RUN/SS
7
PGOOD
2
ITH
3
Ca
se
17
R162
820K
NC
R164
294K
TP65
1
C200
22uF_1210
1
2
C196
1UF_16V
1
2
VIN_PMC_SHDN
R142
100K
SHDN
R141
100K
VIN_PMC
VIN_PMC_SHDN
C58
10nF
1
2
C59
100nF
1
2
Q8A
SI5515DC
2
7
1
8
Q8B
SI5515DC
4
5
3
6