– 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.
In addition the XV1-XV10 signals which are output from IC101
are vertical transfer clocks, and the XSG signal is superim-
posed onto XV1, XV3, XV5 and XV7 at IC901 in order to gen-
erate a ternary pulse. In addition, the XSUB signal which is
output from IC101 is used as the sweep pulse for the elec-
tronic shutter.
Fig. 1-4. IC905 Block Diagram
4. IC905 (H Driver, CDS, AGC and A/D converter)
IC905 contains the functions of H driver, CDS, AGC and A/D
converter. As horizontal clock driver and reset pulse for CCD
image sensor, H1, H2, H3, H4, HL and RG are generated
inside, and output to CCD.
The video signal which is output from the CCD is input to pin
(25) of IC905. 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) 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
47
5
6
7
46
45
58
59
56
57
55
RESET
SUBCNT
SUB
VDC
V6
V4
V5R
V5L
V3R
V3L
V1S
Level
conversion
44
V2
Level
conversion
Level
conversion
Level
conversion
Level
conversion
Level
conversion
Level
conversion
Level
conversion
Level
conversion
Level
conversion
37
VM
12
VM
31
OV6
35
OV4
36
OV2
24
OV5R
26
OV3R
13
VMSUB
23
OV5L
2-level
2-level
2-level
3-level
25
OV3L
2-level
2-level
2-level
2-level
2-level
41
VL
27
OV1S
9
VL
14
OSUB
53
52
51
63
62
61
60
4
2
64
38
8
CH1
CH4
CH7
V3
CH2
CH5
CH8
V5
CH6
CH9
GND
VH
54 V1
Level
conversion
Level
conversion
Level
conversion
Level
conversion
Level
conversion
Level
conversion
Level
conversion
10
19
18
22
15
VH
OV5A
OV5B
OV5C
OV3A
20
21 OV3B
OV3C
3 CH3
3-level
3-level
3-level
3-level
3-level
3-level
3-level
3-level
29
30 OV1A
OV1B
28 OV1C
Level
conversion
Level
conversion
Level
conversion
Level
conversion
Level
conversion
3-level
50
MODESEL