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4. Power Supply Control
The 4-bit microprocessor 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, a regulated 3.2 V
voltage is normally input to the 4-bit microprocessor (IC301) by IC302, so that 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 battery is removed, the 4-bit micro-
processor operates in sleep mode using the backup capacitor (C3050). At this time, the 4-bit microprocessor only carries out
clock counting, and waits in standby for the battery to be attached again. When a switch is operated, the 4-bit microprocessor
supplies power to the system as required.
The 4-bit microprocessor first sets both the P (A) ON signal at pin (3) and the P ON signal at pin (4) to low, and then turns on the
DC/DC converter. After this, High signals are output from pins (7) and (8) so that the ASIC and the SPARC lite are set to the
active condition. If the LCD monitor is on, the LCD ON 1 signal at pin (12) and the LCD ON 2 signal at pin (2) set to Low, and the
DC/DC converter for the LCD monitor is turned on. Once SPARC lite processing is completed, the ASIC and the SPARC lite
return to the reset condition, all DC/DC converters are turned off and the power supply to the whole system is halted.
Power voltage
Power switch OFF
Lens
cover
close
Playback
Power switch ON-
Auto power down
Shutter switch ON
Lens
cover
Resolution, Flash,
open
Self timer switch ON
LCD finder
Power voltage
Lens cover
Power switch OFF
open
Power switch ON-
Auto power down
Take a picture
Lens
Erase image
cover
open
Download image
Continuous image
Message from host
Note) P. SAVE = Power save mode, 1 MHz = Main clock operation, 32 kHz = Sub clock operation
SPARC
ASIC,
Lite
memory
3.3 V
3.3 V
OFF
OFF
ON
ON
OFF
OFF
ON
ON
OFF
OFF
ON
ON
Table 4-3. Camera Mode (Battery Operation)
SPARC
ASIC,
Lite
memory
3.3 V
3.3 V
OFF
OFF
OFF
OFF
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
Table 4-4. Host Mode (Battery Operation)
− 10 −
RS232C
CCD
driver
3.2 V (A)
5 V
(ALWAYS)
+12 V -9 V
OFF
OFF
OFF
ON
OFF
OFF
ON
ON → OFF
OFF
OFF
ON
ON
RS232C
CCD
Driver
5 V (A)
5 V
(ALWAYS)
+12 V -9 V
OFF
OFF
OFF
OFF
ON → OFF
ON
ON
OFF
ON
OFF
ON
ON
ON
ON
4bit
MODE
LCD
CPU
MONITOR
3.2 V
3.2 V
5V (L)
(ALWAYS)
+12V etc.
32KHz
OFF
1MHz
ON
1MHz
ON
1MHz
ON
1MHz
ON
1MHz
ON
MODE
4bit
LCD
CPU
MONITOR
3.2 V
3.2 V
5 V (L)
(ALWAYS)
+12V etc.
32 KHz
OFF
1 MHz
ON
1 MHz
ON
1 MHz
ON
1 MHz
ON
1 MHz
ON
1 MHz
ON
LCD
OFF
ON
OFF
OFF
OFF
ON
LCD
OFF
OFF
OFF
OFF
OFF
OFF
OFF
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