Sony Cyber-shot PRO DSC-D700, Service Manual

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4-18 DSC-D700 (UC,CE)
2. Channel control function
This circuit can independently control a 4-channel power circuit. This time, the
output signal of this circuit can be obtained when the voltage level is high with
pins 20, 21, and 22 connected.
3. Protection functions
1) Timer latch-type short protection circuit
An SCP comparator detects each comparator output voltage level for output
short-circuit detection. When at least one output voltage becomes more than
2.1 V, the timer circuit operates and the external capacitor at the SCP pin (pin
23) begins charging. A latch circuit operates when the output voltage
described above is not restored to the normal voltage until this voltage rises
to the Vbe voltage. After that, an output transistor is turned off, and
simultaneously, the pause period is set to 100 %. The power can be turned
on again for restoration when this protection circuit operates.
2) Malfunction prevention circuit during low-voltage input
The transient state during the power-on sequence or the instantaneous
decrease in a supply voltage causes the malfunction of a control circuit, and
damages or deteriorates the system. This function turns off an output
transistor to prevent a malfunction by detecting the supply voltage level and
resetting a latch circuit.
4. Transformer T601 outputs _ 8.5 V and 15 V of a camera in the winding ratio of a
transformer because a circuit consists of parts on the PS-536 board.
5. Transistors Q605 to Q602 control and drive each power. They cover more than
the output current of each power.
6. The voltage produced on the PS-536 board is sent from each pin of board-to-
board connector CN602 to the unit.
7. As described in the attached paper, connector CN603 is a connector used when
the 2.5-inch liquid-crystal display power and system control power that cannot
be mounted on the PS-536 board because of the space or circuit scale are
mounted on the RM-177 board.
8. An UNREG voltage is sent from the KC-47 board to the CN601 connector
through a harness.