Casio CASSIOPEIA A-20 User Manual

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V3MAIN
VDD
VAMP
P25ON
VLCD-
ONSTATUSB
PLCD
VLCD+
VTH
EVOL 0
EVOL 1
EVOL 2
EVOL 3
VDD
CAP+
V0
1IO 1C
2C
3C
4C
1OI
2IO
2OI
3IO
3OI
4IO
4OI
VDD
L219
Q200
Q201
Q202
Q203 D203
Q204
Q205
D200
FB1
CSW
EXT1
EXT2
RV5 VH3
(IC201)
SCI7660
(IC200)
TC74HC4066 (IC202)
+
+
LCD power Circuit
DC/DC converter RN5VH3 (IC201) generates LCD power and it makes up LCD power system for LCD.
VDD : +3.7 V source for LCD unit.
VAMP : +7.0 V source for LCD unit.
PLCD : Controls ON/OFF of VAMP. From pin 159 of MB87A915 (IC3).
VLCD+: +15.5 V source for LCD unit.
VTH : LCD power source for LCD unit.
EVOL 0-3 : LCD status.
P25ON : Controls ON/OFF of LCD power. From pin 167 of MB87A915 (IC3).
VLCD- : -10.0 V source for LCD unit.
ONSTATUSB : Controls ON/OFF of LCD power. From pin 99 of CPU (IC1).

Casio CASSIOPEIA A-20 Specifications

General

Brand	Casio
Model	CASSIOPEIA A-20
Category	Handhelds
Language	English