Epson 1240U - Control Circuit

EPSON Perfection 1240U Revision A
Operating Principles Control Circuit 20
2.2 Control Circuit
The CPU (IC12) of this scanner is a one-tip 16-bit bus CPU operating at
20MHz. ASIC (IC10) manages input signal correction, image processing, and
controlling the CCD sensor board and USB interface. The power supply control
uses a DC/DC converter to generate 5 V and 12 V signals from the 24 V DC
input. Table 2-1 shows the major IC functions.
Figure 2-5. Control Circuit Diagram
Table 2-1. Major ICs
IC Location Functions
M37920 IC12
CPU
24-bit Address Bus
16-bit Data Bus
MB81F6416420-102 IC13 SDRAM 4M x 16bit
IS61C6416 IC17 SRAM 64k x 16bit
E02A32SA IC10
ASIC: Manages the following:
• Input image signal correction
• CCD control
•Line control
• Image processing
• Memory control
• Data in/output control
A3957SLBTR IC4,5 CR motor driver IC
M51953A IC11 Reset IC
M27C1001-10F1 IC9 PROM 4M x 8bit
IS61C256AH IC16 SRAM 32k x 8bit
GP1S58V PC1 CR home position sensor
NJM2360 IC1,2 DC/DC Converter
AD9822 IC19 8bit A/D Converter
E02A35BA IC14 USB interface control
SSR20.00BA CR1 Clock 20MHz
NJM78M12 IC8 Regulator (12VDC)
CCD Board
Lamp
&
Inverter Board
Image Data
(R/G/B)
8-bit
Data
E02A34EB (IC10)
SRAM
(IC17)
SDRAM
(IC13)
(
IC16
)
(
IC9
)
(
PC1
)
CPU (IC12)
CLK(CR1)
CR Motor
Driver
(IC4,5)
CR
Motor
PROM
USB
Controller
(IC14)
USB
Reset IC
(IC11)
SRAM
H.P.
A/D
Converter
(IC19)
+24VDC
Regulator
(IC8)
+12VDC
+24VDC
DC/DC
Converter
(IC1,2)
+5VDC
Address Bus
Data Bus
Option
Sensor