Nikon Coolpix 5700 Repair Manual page 41

4. Power Supply Control
The 8-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 regu-
lated 3.2 V voltage is normally input to the 8-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 8-bit microprocessor opererates in clock backup mode using the backup lithum ion battery.
At this time, the 8-bit microprocessor only carries out clock counting, and waits in standby for the battery to be
attached again. When a switch is operated, the 8-bit microprocessor supplies power to the system as required.
The 8-bit microprocessor first sets both the P (A) ON signal at pin (70) and the P ON signal at pin (71) to High, and
then turns on the DC/DC converter. After this, the ASIC RESET at pin (97) and the MAIN RESET at pin (91) set to
High, so that the ASIC and the SPARC lite are set to the active condition. If the LCD monitor is on, the LCD ON
signal at pin (14) and the LCD BL signal at pin (58) set to High, and the DC/DC converter for the LCD monitor is
turned on. If EVF is lighting, the EVF ON signal at pin (10) and EVF BL signal at pin (11) set to High. LCD
monitor and EVF are not turned on simultaneously. If a video jack is inserted, LCD and EVF turn off. 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.
MODE Power voltage
OFF
SLEEP
Display
PLAY
mode
Video output
Display
REC
mode
Video output
SPARC
Memory
Lite
3.3V
3.3V
1.8V
OFF OFF
LCD ON ON
EVF ON ON
ON ON
LCD ON ON
EVF ON ON
ON ON
- E7 ･ E5700 -
CCD 8 bit CPU
15.1V(A)
3.2V
-7.7V(A)
(ALWAYS)
5.1V(A)
OFF 32KHz
3MHz
OFF
32kHz
3MHz
OFF
32kHz
3MHz
OFF
32kHz
3MHz
ON
32kHz
3MHz
ON
32kHz
3MHz
ON
32kHz
Table 4-3. Power
VAA11801-R.3578.A
MODE LCD
LCD MONITOR MONITOR
3.2V 12V(L) 12V(E)
OFF OFF
ON ON
ON OFF
ON OFF
ON ON
ON OFF
ON OFF
EVF
OFF
OFF
ON
OFF
OFF
ON
OFF