1-10 (E)
BVP-E30/E30P M-V1
1-7. Circuit Description
1-7-1. CCD Block (PA-272/273/274 Boards,
TG-229 Board, and NR-72 Board)
PA-272/273/274 Boards
The PA boards contains the CCD bias circuit, horizontal
register drive circuit (H1, H2, LH1 driver), CDS (Correlat-
ed Double Sampling) circuit which extracts video signals
from the CCD and eliminates noise, and preamp circuit
which adjusts sensitivity.
IC9 of PA-273 board detects temperature around the CCD
block with a temperature sensor, and sends the detected
signal to the AT-148 board.
Various CCD drive conditions, adjustment data (V-sub
voltage, RG voltage, black/white shading, etc.) are written
in IC8 (EEPROM) of PA-272 board.
TG-229 Board
The TG-229 board contains the CCD drive pulse genera-
tion circuit and its drive circuit.
The 18 MHz clock generated from the voltage control
generation circuit (X1) is sent to the DPR-261 board to
generate the AHD, AVD pulse synchronized with the
video output signal.
The TG IC (IC1) generates the CCD drive pulse synchro-
nized with this AHD, AVD pulse and the sample and hold
pulse for the CDS circuit of the PA boards.
These pulses are passed through the following drive circuit
and are sent to each PA board.
.
V clock: Passed through IC201 to IC206 drivers ICs
.
RG pulse: Passed through IC309 and then the bias
potential specific to each. CCD is added to the
output of IC309.
.
V-sub voltage:
Enters IC310 DC amplifier to be adjusted for
the specified voltage.
.
Shutter pulse:
Passes through the drive circuit consisting of
Q201 to Q204.
.
SHP/SHD/H1/H2/LH1:
Passes through IC312, IC313, and IC307
AND gate ICs.
NR-72 Board
The NR-72 board contains a power stabilization circuit to
stabilize various power supply voltages to be supplied to
the CCD block, black/white shading correction signal
generation circuit, and optical filter interface circuits.
.
The power stabilization circuit stabilizes the following
power supply voltages to be supplied to the CCD block.
+
15.0 V
+
30.0 V
+
6.0 V
+
5.3 V
+
3.3 V
+
2.5 V
+
1.8 V
+
1.1 V
_
10.0V
_
8.0 V
_
4.5 V
.
The black/white shading correction signal and TEST
SAW signal are generated in IC104, and are sent to the
VA-226 board to mix with the video signal.
.
This board has two optical filter interface circuits, one is
for the two-filters type with a servomotor used in the
BVP-E30/E30WS/E30WSP, the other is for one filter
type without a servomotor used in the BVP-E30P.
The switch S101 switches these circuits.