Sanyo VPC-S122EXBL Service Manual page 7

5. Key Operaiton
For details of the key operation, refer to the instruction manual.
IN
OUT
0
1
2
6. Power Supply Control
The following is a description of how the power supply is turned on and off.
When the battery is attached, IC181 is operating and a regulated 3.1 V voltage and subclock (32.768 kHz) input to the ASIC.
When the power switch is off, halt high-speed internal ocillation clock (48 MHz), so that key input monitoring for the camera can
start up again.
When the battery is removed, halts high-speed ocillation clock, and operates clock counting only RTC signal in the IC181 by the
secondary battery for memory backup .
Also, the secondary battery for backup is charged when it to be attached.
When the power switch is on, the ASIC starts processing. First set the PON and PON2 signals to High, and then turn on the
digital system power circuit. And after the ASIC operates high-speed oscillation clock, and then turn on the analog system power
by serial settings of power IC.
When the power switch is off, PON signal to Low and the power supply to the whole system is halted, set operation mode of clock
ocillation of subclock.
At this time, the ASIC sets PON2 to High so that the 1.8 V continues to be supplied. The preserves the contents of the DDR
memory so that high-speed starting up can occur during the next start-up (self-refresh).
Power supply voltage
Power OFF
Power OFF (Self refresh)
Playback mode
Shooting mode
USB connection
8. LCD Backlight Energy Saving Control
This switches the LCD luminance (backlight current) according to menu operations.
Switching of the backlight luminance is carried out the serial settings of power IC by ASIC to vary the current value for the LED.
1
0
MENU
OK
DOWN
LEFT
TELE
WIDE
Table 2-1. Key Operation
3.1 V
ON
ON
ON
ON
ON
Table 2-2. Power supply control
2 3
PLAY SCENE
UP RIGHT
PW_TEST TEST
ASIC,
memory
1.1 V, 3.25 V,
1.8 V
1.8 V (LVDS)
OFF
OFF ON
ON
ON
ON
– 7 –
LCD
CCD
MONITOR
12 V, 14V,
3.25 V
-6 V, 3.4 V
OFF OFF
OFF OFF
OFF ON
ON ON
OFF
ON