– 4 –
Fig. 1-3. IC901 Block Diagram
3. IC905 (H Driver) and IC901 (V Driver)
An H driver (a part of IC905) and V driver (IC901) are neces-
sary in order to generate the clocks (vertical transfer clock,
horizontal transfer clock and electronic shutter clock) which
driver the CCD.
IC905 has clock generating which drives horizontal CCD and
its drives function. These clocks are output from pin (14), (15),
(18) and (19) of IC905. In addition the XV1-XV10 signals which
are output from IC101 are the vertical transfer clocks, and the
XSG1A, XSG1B, XSG2A, XSG2B, XSG2C, XSG3A and
XSG3B signals which are output is superimposed onto XV1,
XV3, XV5, XV7 and XV9 at IC901 in order to generate a ter-
nary pulse. In addition, the XSUB signal which is output from
IC101 is used as the sweep pulse for the electronic shutter,
and the RG signal which is output from pin (21) of IC905 is
the reset gate clock.
4. IC905 (CDS, AGC Circuit and A/D Converter)
The video signal which is output from the CCD is input to
pins (27) of IC905. There are S/H blocks inside IC905 gener-
ated from the XSHP and XSHD pulses, and it is here that
CDS (correlated double sampling) is carried out.
After passing through the CDS circuit, the signal passes
through the AGC amplifier. It is A/C converted internally into
a 12-bit signal, and is then input to IC101 of the CP1 circuit
board. The gain of the AGC amplifier is controlled by pin (31)-
(33) serial signal which is output from IC101 of the CP1 board.
Fig. 1-4. IC905 Block Diagram
CCDIN
RG
H1-H4
VD
HD
SDATA
SCK
SL
CLI
HBLK
CLP/PBLK
DOUT
VRB
VRT
PRECISION
TIMING
CORE
SYNC
GENERATOR
PxGA
VGA
12-BIT
ADC
12
6~42 dB
VREF
CLAMP
INTERNAL
REGISTERS
INTERNAL
CLOCKS
CDS
HORIZONTAL
DRIVERS
4
0~18 dB
AD9949
C1
F2
F1
E2
E1
D2
D1
B1
L3
L2
A4
VL2
XV5N
DVD1
AVD1
XSUBN
XSG9N
XV2N
XSG7N
XV7N
XSG5N
Input Buffer
AVS1
G10
XV3N
F11
XSG3N
F10
XV1N
A6
VH2
A10
VM2
C2
SUB
E11
XSG1N
E10
XV4N
D11
XV9N
K9
XSG10N
K11
J2
J1
H2
H1
G2
H10
H11
J10
J11
XV8N
XV6N
XSG8N
XSG6N
XV13N
XV12N
XSG4N
XV11N
XSG2N
XV14N
K1
XV10N
B11
AVS2
C11
AVD2
L10
DVD2
A2
V2
B4
V7A
A5
V5A
B6
V3A
A8
V1A
B8
V4
A9
V9
C10
V6
B9
V7B
B7
V5B
A7
V3B
B5
V1B
A3
V8
B3
V10
L4
VM1
L5
VH1
L7
VL1