Epson SEIJ98006 14. Major Components on the C265 Main Board 1/2, EPSON Stylus Color, Revision C

EPSON Stylus Color 900 Revision C

The following tables list the major components on the C265 main board and their functions.

Table 2-14. Major Components on the C265 Main Board (1/2)

Component	Functions
	• A Hitachi H8-series CPU.
CPU:	• Performs high-speed data processing running at 24.0
	Mhz with an external transmitter.
	• Bus width is 16-bit.
ASIC 1:	• Controls all interfaces but USB.
(E05B60: IC3)	• Monitors the signal from each sensor.
ASIC 2:	• Controls printheads, motors, ASF solenoid, cooling fan,
(E05B59: IC2)	USB I/F, and EEPROM.
	• For PROM, either one-time PROM or Mask ROM is
	used. Specifications vary depending on the
	destinations, as shown below:
	<Standard version>
	• PROM size: 16 M bit
PROM/MROM:	• Contents: Unattached
	• Bus width: 16 bit
	<NLSP version>
	• PROM size: 16 M bit
	• Contents: 16 M bit
	• Bus width: 16 bit
D-RAM:	• Manages the various buffers and work area.
	• Bus width is 16 M bit.
	• Counts total power off time of the printer, which offers
	the basis for determining the cleaning type to be
	performed at the next power on. Power is supplied by
	an external button-cell battery (a lithium battery). This
Timer IC:	IC also serves to produce reset signals connecting to
(RTC9810: IC8)	each major IC, such as CPU, ASIC1, ASIC 2, and motor
	drive ICs. The head driver ICs (CXA2128 x 2: IC15 and
	IC16) individually produce a reset signal when detecting
	abnormal voltage so the printhead can stop in the
	proper sequence.

Table 2-15. Major Components on the C265 Main Board (2/2)

Component	Functions
	• The LB1847 (IC11 and IC12) is used to drive PF motor
	and CR motor and enables 4W1-2 phase excitation
	mode for the first in EPSON line. This control system,
	called micro stepping, materializes the control of the
Motor driver IC	carriage vibration during printing and improvement of
(LB1847: IC11, 12)	accuracy in paper feeding on the hardware basis.
(A3957: IC13, 14)	• The A3957 (IC13 and IC14) used to drive Pump, ASF
	motor also supports the 4W1-2 phase excitation mode on
	the hardware basis, but differs from the former IC in the
	point that the IC13 and IC14 individually excite the phase
	A and B.
	• The head driver ICs, directory attached to the board,
	consist of two separate circuits; charging circuit and
	discharging circuit, to produce trapezoidal waveform.
Head driver IC	This IC creates the trapezoidal waveform by combining
(CXA2128 x 2: IC15,	the signals input from the input port E05B59 (IC2) of the
16)	IC. This is performed to change the characteristics and
	voltage levels of charging and discharging, and the
	trapezoidal waveforms specific to normal dot print and
	micro dot print are produced as the result.

Operating Principles Electrical Circuit Operation Principles 60