Sony MZ-E30, Service Manual

Page: 35 / 72

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5-5. RESET Circuit
Fig. 5-7. shows the RESET circuit and the RESET signal timing. The 2.8V (VC) obtained in the step up power supply
circuit of the motor driver (IC551) enters the RESET circuit after being divided with a resistor inside via Pin
0
[VC] in the
DC-DC converter (IC901). In the RESET circuit, the capacitor connected to Pin
7
[CRST] outputs the RESET signal from
Pin
8
[XRST] to main ICs, such as system controller (IC801) and DSP/digital servo (IC601), at the delayed timing shown in
the figure.
Fig. 5-7. RESET Circuit and RESET Signal Timing
1
2
VC
RESET
2.7[V]
6[ms]
0
0
2.8[V]
from SERVO DRIVER IC551
, pin VB1
VC
IC901
DC-DC CONVERTER
10
1
GND
7
CRST
C903
8
XRST
XRESET
9
IC801
SYSTEM CONTROLLER
30
RESET
IC601
DSP/DIGITAL SERVO
3
PD
IC301
D/A CONVERTER
24
RESET
IC501
RF AMP
7
IC802
EEPROM
PE
2
1
RESET
3 2