n Overview
The AN3497SB is a chroma noise reduction (CNR) IC
for VCR and uses a chroma recursive filter system. In
combination with the AN2260 (luminance signal process-
ing), AN2460 (chroma signal processing), etc., it config-
ures a VHS signal processing system.
n Features
• Capable of meeting with the NTSC/PAL system.
• Capable of meeting with the EDIT mode and THRU
mode.
• The CNR limiter level and CNR output level can be adjust-
ed depending on external DC.
• The feedback constant (KC) can be set optionally depend-
ing on an external resistor.
• The chroma signal can be adjusted depending on an
external resistor.
• Built-in functions such as Y vertical correlative signal
detector, etc.
1
ICs for VCR
AN3497SB
Chroma Noise Reduction IC
1
89
16
0.35
–
0.1
0
.8
0.1
–
0.1
4.3– 0.3
6.3– 0.3
0.5
0.15
0.65
1.5
–
0.2
6.5
–
0.3
Unit : mm
16-Pin PANAFLAT Package (SSOP-016-P-0225a)
16 15 14 13 12 11 10 9
1 2 3 4 5 6 7 8
V
CC
GND
EF
0dB
A2
LPF
Det.
SW
GCA
B1
8.1dB
CEQ –2.1dB –13.2dB
20dB 20dB
A1
CTL
COR
–20.8dB
–2.1dB
–13.2dBB2
Lim.
–9.5dB
22kW33kW
– 0.8dB
n Block Diagram