HA11560FP Hitachi Semiconductor, HA11560FP Datasheet - Page 7

• Manufacturer Part Number: HA11560FP
• Description: VCR/VDP RF Modulator
• Manufacturer: Hitachi Semiconductor

Audio Modulator
Pins 4 and 5 make up the reference oscillator for
the 4.5 MHz audio modulator. Pin 4 is the
oscillator ’s reference bias source. A 15 pF
capacitor must be used for C3 at pin 4 to cut the ac
signal. The oscillation frequency is determined by
an external tank circuit.
Figure 5 Audio Modulator Interface Circuit
2 k
C3
15 p
4
200
T1
Audio oscillator
5
Audio amplifier
Audio input
6
100 k
100
R5
330
V
CC
An external cuppling capacitor is not required
when pin 6, which is the audio input pin, is almost
equal to ground potential and the audio input
signal dc level is ground potential. The ground
potential of the input pin results in a circuit
configuration that reduces pin 6 voltage
fluctuations and suppresses popping noise.
HA11560FP/T
7