LA7567N Datasheet, PDF (11/14 Pages) Sanyo Semicon Device – TV and VCR VIF/SIF IF Signal-Processing Circuit with PAL/NTSC Multi-Format Audio Support

Continued from preceding page.
Pin No.
Pin
LA7567N, 7567NM
Description
• First SIF AGC filter connection.
This IC adopts an average value AGC technique. The first
SIF conversion gain is about 30 dB, and the AGC range is
over 50 dB. A 0.01 µF capacitor is normally used in filter
16
1st SIF AGC FILTER
connected to this pin.
• When used in an intercarrier system:
Connect this pin (pin 16) to ground. The IC internal switch
will operate to connect the intercarrier output to the SIF
converter input.
Equivalent circuit
• IF AGC filter connection
The signal peak-detected by the built-in AGC detector is
converted to the AGC voltage at pin 17. Additionally, a
17
IF AGC FILTER
second AGC filter (a lag-lead filter) used to create the dual
time constants is provided internally in the IC.
Use a 0.022-µF capacitor as the external capacitor, and
adjust the value according to the sag, AGC speed, and
other characteristics.
• VIF amplifier input.
18
19
VIF input
The input circuit is a balanced circuit, and the input circuit
constants are:
R ≈ 1.5 kΩ
C ≈ 3 pF
20
GND
Continued on next page.
No. 5765-11/14