Sanyo VPC-X1420EXR Service Manual page 7

5. Key Operaiton
For details of the key operation, refer to the instruction manual.
IN
OUT
0
SCENE
1
2
6. Power Supply Control
The ASIC controls the power supply for the overall system.The following is a description of how the power supply is turned on
and off.
When the battery is attached, IC501 is operating and a regulated 3.2 V is input to ASIC (IC101). Clock counting and key scanning
is carried out even when the power switch is turned off, so that the camera can start up again.
When the power switch is off, the ASIC operates 32.768 kHz of subclock.
When the battery is removed, the ASIC power switches the secondary lithium battery for memory backup by IC181, and operates
at low consumption. At this condition, 32.768 kHz of subclock operates clock counting.
Also, the battery for lithium backup is charged 10 hours from it to be attached.
When the power switch is on, the ASIC starts processing. The ASIC first sets the PON signal and PON2 signal to High, and then
turn on the power circuit. After PON signal is to High, carry out setting of the operating frequency and oscillation control inside the
ASIC.
During through screen operation, the serial communication and PAON3 signal are set to High and the CCD power supply starts
up.
During playback, CCD power supply is turned off.
When LCD panel turns on, the serial communication turns on the backlight power.
When the power switch is off, the lens will be stowed, and the power supply to the whole system is halted. The ASIC set operation
mode of clock ocillation (32.768 kHz).
Power supply voltage
USB connection
7. Auto-refresh function
If the power is turned off while the battery is still inserted, this model keeps running at 1.8 V and controls auto-refreshing of the
DDR with the aim of reducing the time required for startup.
While DDR auto-refresh control is being carried out, only PON2 is set to High and only VDD1.8V is started up, even if the power
supply which controls PON and serial communication is at Low.
1
0
WIDE
RIGHT
OK
-
-
Table 2-1. Key Operation
Power OFF
Playback mode
Shooting mode
Table 2-2. Power supply control
2 3
TELE MENU
UP DOWN
- PW_TEST
ASIC,
memory
1.1 V, 1.8 V,
3 V
OFF
ON
ON
ON
– 7 –
4
PLAY
LEFT
TEST
LCD
CCD
MONITOR
+13 V, -6 V,
3 V
3.3 V
OFF OFF
OFF ON
ON
ON
OFF ON