EPSON Stylus Photo 720 / EPSON Stylus Photo EX3
Revision A
Operating Principles
Electrical Circuit Operating Principles
45
2.2.2.1 Main elements
Table 2-8 shows the main elements on C301MAIN.
2.2.2.2 Printhead Driver Circuit
The printhead driver circuit consists of the following two components:
n
Head common driver circuit
(Common driver IC15 & Wave amplifier transistor Q2, 3)
n
Nozzle selector IC on the printhead driver board.
The common driver (IC15) generates a reference drive waveform according to the
output signals from the ASIC (IC2). The reference drive waveform is amplified by the
transistors Q2 and Q3 and then transferred to the nozzle selector IC on the head board.
Print data is converted to serial data by the ASIC and then sent to the nozzle selector IC
on the head board. Based on the serial data, the nozzle selector IC determines the
nozzles to be actuated. The selected nozzles are driven by the drive waveforms
produced by the common driver. See Figure 2-14 for the printhead driver circuit block
diagram.
Table 2-8. Main Elements
IC
Location
Function
CPU
HD64F/2328F
IC1 (3.3V)
16bit CPU mounted on the MAIN board is driven by
clock frequency 24MHz and controls the printer.
Gate Array
E05B70**
IC2
(3.3V & 5.0V)
• Motor Control
• Head voltage control
• EEPROM control
• Sensor supervise
• Timer IC supervise
• Parallel I/F, USB I/F control
PROM
IC3 (3.3V)
• Capacity 4/8/16MB, Bus= 16 bit EEPROM
• Program or p CG (Character generator)
RAM
IC17 (3.3V)
Bus= 16 bit, 4Mbit DRAM
AT93C56
IC6 (5.0V)
2kbit EEPROM
• Default value setting
• Parameter backup
RTC-9810SA
IC5 (5.0V)
Reset/ Timer IC
• For +5V; reset when +4.3V is detected
• For +42V, reset when +35.5 is detected
• Timer function is attached powered by lithium
battery.
74V161284
IC9 (5V)
IEEE1284 parallel I/F transceiver IC
PDIUSBP11A
IC10 (3.3V)
USB Rev1 transceiver
LB11847
IC13
CR motor drive IC
LB11847
IC14
PF/ PUMP/ ASF motor drive IC
CXA2128S
IC15
Head drive control HIC
• Generates head common voltage.
Summary of Contents for Stylus Photo 720
Page 5: ...Revision Status Revision Issued Date Description Rev A April 6 2000 First Release ...
Page 8: ...C H A P T E R 1 PRODUCTDESCRIPTION ...
Page 29: ...C H A P T E R 2 OPERATINGPRINCIPLES ...
Page 51: ...C H A P T E R 3 TROUBLESHOOTING ...
Page 64: ...C H A P T E R 4 DISASSEMBLYANDASSEMBLY ...
Page 94: ...C H A P T E R 5 ADJUSTMENT ...
Page 114: ...C H A P T E R 6 MAINTENANCE ...
Page 121: ...C H A P T E R 7 APPENDIX ...
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