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2-4. Power-On Reset Circuit
Immediately following power-on the printer executes a power-on reset, initializing all circuit elements. The power-on reset
serves as protection against operational errors. The power-on RESET signal is maintained for approximately 160ms.
The reset circuit is illustrated below.
Fig. 2-10 Power-On Reset Circuit
(1) At power on, voltage-detector circuit IC4 (M51953BL) outputs a LOW signal from its OUT terminal.
The following formula is used by capacitor C2 (0.47µF).
T = 0.34 × C2 (pF) [µs] = 160ms
(2) The LOW signal resets the CPU and the mechanism drive circuits.
(3) The LOW signal sets S-RAM into backup status (Ver.1 only).
+5V
IC4
CD
C2 GND
+5V
+5V
+5V
VCC
RESET
DD3
IC5 : CPU
RES RESO
RESET
VCC
S-RAM
+
Gate
Array
IC1
RESET IC
IC10
Protection
Circuit
CPU