Samsung MSYS 5150, Service Manual

Page: 73 / 210

PIN Name PIN No. Description
X C L K 35 IP_CLK(30MHz) input from OSC.3
/RESET 2 /RST_OUT input from U1-178
SI 89 From line scanning to start signal output at 2.5mS intervals
CLKI 91 Supply 1MHz to CIS clock output
/ T R D R E Q 118 External DMA request signal output
/ T R D A C K 117 External DMA acknowledge input
V R E K D A C 97 Top standard voltage (+Vref) input of A/D converter
A D C I N 96 Analog signal input of CIS
VREFA D C 102 Bottom standard voltage (-Vref) input of A/D converter
TX_A1 105 Scan motor driver control signal, TMIA0 output
TX_B1 106 Scan motor driver control signal, TMIA1 output
TX_A2 107 Scan motor driver control signal, TMIB0 output
TX_B2 108 Scan motor driver control signal, TMIB1 output
TX_EN1 109 Scan motor driver control signal, TMPHA output
TX_EN2 110 Scan motor driver control signal, TMPHB output
TX_INT 111 Scan motor interrupt output
Samsung Electronics 5-25
5-2 Scanner Part
Circuit Description
Fig.5-12 CIS Driver Clock Timing
5-2-1 Summary
Scanner part consists of image sensor which input
graphic signal using CIS (Contact Image Sensor),
scanner control signal, image processing by using
image processor, SCAN_IP. Data flow of scanner part,
block diagram of SCAN_IP, I/O port and circuit
description are as follows.
5-2-2 CIS Driver, Input Processor
CIS driver consists of /LED_GND1, 2, 3, CIS_CLK,
CIS_SH. CIS driver power supply is 12V, LED driver
power supply is 5V. Especially, /LED_GND1, 2, 3
are enable to control voltage from U18 using Q1 in
CLED signal.
As CIS input signal, minimum (-V
ref
)values supply
about 0, Maximum (+V
ref
)values supply about 1.5V
to voltage divider (R70, R71) through OP-AMP
(U16-3, 1).
Image signal from CIS supply to U31-96 through
CN3-1, U5-5, U5-7, and R75.