AN8946SB Datasheet, PDF (9/10 Pages) Panasonic Semiconductor – FM demodulation IC for BS/CS broadcasting

ICs for TV
s Terminal Equivalent Circuits (continued)
Pin No.
Equivalent circuit
25
25
10 kΩ
1 kΩ
100 µA
AN8946SB
Description
AFC output R
• Outputted is a center point potential of
a loop amp. output dynamic range.
• Also used as a reference power supply
for video amp.
Voltage
(Open)
1.5 V
26
AFC LPF2
1.5 V
26
• Construct a filter with an output im-
pedance approximately 500 kΩ at pin
500 kΩ
1 kΩ
26 and an external capacitor between
pin 26 and pin 27.
100 µA
27
10 kΩ
AFC LPF1
• Low impedance (approximately 0.7
V) for low-level (0 V) of pin 1
• High impedance (floating) for high-
level (0.5 V) of pin 1
0.6 V
500 Ω
27
200 Ω
28
20 kΩ
Key pulse LPF
0V
• Pin to smooth a key pulse
• Identifying a key pulse by this pin.
50 kΩ
28
1 kΩ
9