Power Supply - Canon CANOSCAN N1220U Service Manual

V. POWER SUPPLY
The scanner draws its power +5V from USB interface. +5V is used for the digital circuit in
the main PCB.
Power supply to the analog circuit is ON/OFF controlled by the gate array. Drive motor,
contact image sensor, and analog circuit are supplied with power as necessary. 5.5V step up
circuit in the main PCB is used for the analog circuit and for driving the contact image sensor.
Host comuter
+5V
USB
port
COPYRIGHT 2000 CANON INC.
Main PCB
5.5V step up circuit
Gate
array
Figure 2-24
CANOSCAN N650U/N656U/N1220U REV.0 JUNE 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)
5.0V reference voltage
Analog circuit
Digital circuit
CHAPTER 2
Drive motor
LED
Contact image
sensor
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