HA11560 Datasheet, PDF (5/10 Pages) Hitachi Semiconductor – VCR/VDP RF Modulator

HA11560FP/T
Block Operation Descriptions
The following describes the operation of each
block and external circuits.
Video Clamp
The video clamp circuit employs a sync peak value
clamp. Input impedance is at a level of
approximately 30 kΩ to reduce compression of the
sync pulse. Note that sag is generated in the sync
pulse when a capacitor of 0.47 µF or lower is used
for C10 at pin 16.
White Clip Circuit
The white clip level is set to 92.5%. A circuit that
produces a sharp white clip is used in order to
produce high linearity characteristics for the video.
Increasing the white clip frequency characteristic
by another 5 MHz eliminates video carrier cutoff
by the chroma signal and prevents deterioration of
audio buzz characteristics.
Video in
+ ₁₆
C10
1 µF
White clip
circuit
White clip level
HA11560
white clip
characteristics
Normal
white clip
characteristics
Figure 1 Video Input Circuit
Figure 2 White Clip Characteristics
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