Epson Stylus C110 - C687 Main Board

EPSON Stylus C110/C120/D120 Revision B
OPERATING PRINCIPLE Electrical Circuit Operating Principles 36
2.3.2 C687 Main Board
The logic circuit of the C687 main board consists of the following components.
 Logic line
(CPU-ASIC, SDRAM, FlashROM, etc.)
 Motor control/drive circuit (CR motor/PF motor)
 Head control/drive circuit
 USB Interface control circuit
 Sensor circuit
 Reset circuit, EEPROM circuit
The printer mechanism is controlled by the above circuits. Following describes the
major characteristics of the main board.
 Streamlining with no complex circuit
The main board includes the reset circuit and EEPROM circuit independently.
This simple configuration is achieved because RTC is not required for the Stylus
C110/C120/D120, which does not have stand-alone direct print function.
 Power save mode
The main board reduces power consumption by carrying out the followings in the
power save mode.
 Partially stops the ASIC clock
 Brings the motor driver/head DAC into sleep/standby mode
 Stops energizing motors
 Brings the SDRAM into the self-refresh mode
2.3.2.1 Major Components on Main Board
The table below lists the major components on the C687 main board.
Table 2-6. Major Components on Main Board
IC Location Function
Flash ROM IC1
4Mbit
• Stores the firmware
SDRAM IC2
64Mbit
• bus: 16bit
Reset IC IC3 Monitors voltage on 42V line and 3.3V line.
CPU-ASIC IC8
Drives at 96MHz (internal)/48MHz (external) of clock frequency
and controls the printer mechanism, SDRAM and USB.
EEPROM IC9
2kbit
• Stores various mechanical settings
Motor driver IC5
• CR/PF motor drive IC
• Reduces 42V line to 3.3V/1.5V
Head driver IC13 DAC that generates printhead drive waveform