Board - Sony DXC-390 Service Manual

3-5. MB-875 Board
The MB-875 board is installed the oscillator circuit for
master clock, the timing generator for the CCD driving
pulse, the IC generated detection boundary and the DC-DC
converter.
. . . . . 28 MHz oscillating circuit
This circuit consists of the P-COMP (HD phase compar-
ative output) signal and PLL in VCO.
When the internal sync and VBS external sync, it iscrys-
tal type VCO, HD and VD. When the external sync, it is
generated 28 MHz of the master clock in the LC type
VCO oscillator.
Both oscillator circuits do not operate simultaneously.
The oscillator clock improves the duty ratio in IC635,
IC636 and its around circuit.
. . . . . Timing generator (IC611)
28 MHz and AHD/AVD from the DP-313 board are
input, each pulse for driving the CCD is generated.
. V1, V2, V3 and V4
. H1 and H2
. VSUB
. RG
The transfer pulse is sent via H-driver circuit (IC612)
and V-driver circuit (IC601, IC604 and IC607) to the PA
board, the sample and hold pulse are sent to the VA-193

board.

. . . . . CXD9115AR (IC606)
The window signal for detection frame is generated.
H-Window and V-Window signals are mixed in IC628
and IC629, are output to the DP-313 board.
A CCD accumulative time is realized according to a
trigger input.
. . . . . DC-DC converter (DD601)
The voltages of +15V, +9V, +5V (A), +5V (D), +3.3V
and _7.5V are generated from the external input power
supply UNREG (+), so that supply to each board.
Independently, UNREG (+) is passed through a filter, it
is supplied as UNREG (LENS).
3-4 (E)
Vertical transfer pulse
Horizontal transfer pulse
Electric charge sweep out pulse
Reset gate pulse
DXC-390/390P