– 4 –
Fig. 1-3. IC901 Block Diagram
3. IC901 (V Driver)
A V driver (IC901) is necessary in order to generate the clocks
(vertical transfer clock and electronic shutter clock) which
driver the CCD.
The signals (SCLK, SAV 0-2 and SDV 0-5) which are output
from IC101 are source of the vertical transfer clock, and are
decorded and superimposed at V driver.
The SUBCLK signal which is output from IC101 is used as
the sweep pulse for the electronic shutter.
Fig. 1-4. IC902 Block Diagram
4. IC902 (H Driver, CDS, AGC and A/D converter)
IC902 contains the functions of H driver, CDS, AGC and A/D
converter. As horizontal clock driver and reset pulse for CCD
image sensor are generated inside H1, H2, H3, H4 and RG
and output to CCD.
The video signal which is output from the CCD is input to pin
(25) of IC902. There are sampling hold blocks generated from
the SHP and SHD pulses, and it is here that CDS (correlated
double sampling) is carried out.
After passing through the CDS circuit, the signal passes
through the VGA (VGA: Variable Gain Amplifier). It is con-
verted internally into a small-amplitude actuating signal
(LVDS), and is then input to IC101. The gain of the VGA am-
plifier is controlled by pins (32), (33) and (34) using serial
signals which is output from IC101.
CCDIN
HL
H1 TO H4
HD
SDATA
SCK
SL
REFB
REFT
PRECISION
TIMING
GENERATOR
SYNC
GENERATOR
VGA
12-BIT
ADC
6~42 dB
VREF
CLAMP
INTERNAL
REGISTERS
INTERNAL
CLOCKS
CDS
HORIZONTAL
DRIVERS
4
AD9971
-3, 0, +3, +6dB
VD
CLI
RG
GP01
3V INPUT
1.8V OUTPUT
LDO
REG
GP02
TCLKP
REDUCED
RANGE
LVDS
OUTPUT
TCLKN
DOUT0P
DOUT0N
DOUT1P
DOUT1N
OV0
OV1
XSG0
XSG1
3
3
OV2
XV2
HlDrv0
2
XV0
OV3
OV4
XSG2
XSG3
3
3
OV5
XV5
HlDrv1
2
XV3
OV6
OV7
XSG4
XSG5
3
3
OV8
XV7
HlDrv2
2
XV6
OV9
OV10
XSG6
XSG7
3
3
OV11
XV9
HlDrv3
2
XV8
OV12
OV13
XSG8
XSG9
3
3
OV14
XV11
HlDrv4
2
XV10
OV15
OV16
XSG10
XSG11
3
3
OV17
XV13
HlDrv5
2
XV12
XV14
OV18
OV19
XSG12
XSG13
3
3
OV20
XV16
HlDrv6
2
XV15
XV17
OV21
OV22
XSG14
3
2H
OV23
HlDrv8
2H
XV18
XV20
HlDrv7
XV19
OV24
HlDrv9
2H
XV21
SUBCLK
XSUBCLK
3
XSUBMID
EP
NOTE
: 3 DENOTES THREE-LEVEL DRIVERS
2 DENOTES TWO-LEVEL DRIVERS
2H DENOTES 2-LEVEL HIGH LOAD DRIVERS
DECODER
SAV2
SAV1
SAV0
SDV5
SDV4
SDV3
SDV2
SDV1
SDV0
SCLK
RESET
CCDVH
CCDVM1
CCDVM2
CCDVM3
CCDVL
SUBH
SUBM
DVDD