FIlter Block
Since the sound signall from the CPU is a stepped waveform, the filter block is added to smooth the
waveform.
VDD
2SC3112B
10K10K6.2K
From the CPU
C562(H)
1K
C331JC222(H)
To main volume
AGAGAG
Initial Reset Circuit
When batteries are set or an AC adapter is connected, the reset IC provides a low pulse to the CPU.
The CPU then initializes its internal circuit.
Battery set
VDD
CPU
Reset IC
MSM6626-01
S8053ANO
LSI1
IC4RESET
Power On/Off Circuit
When the power switch is turned on, a low level differential pulse is provided to terminal MI of the CPU.
Upon receipt of the pulse, the CPU starts the power ON sequence and raises the APO signal to +5 V.
When the switch is off, on receiving the KO11 signal at terminal KI0, the CPU drops the APO signal to
ground level to shut down power.
VDDVDD
ON
Power Switch
OFF
MI
ONCPU
KO18
MSM6626-01
KI0
APO signal
OFF
KI1LSI1 OFF: 0V
ON
ON: +5 V
KO11
N 5 N |
ACEC
