U2861B
Mono FM Sound Demodulator for TV Systems
Description
The U2861B is an alignment-free FM sound IF demo-
dulator for all TV standards from 4.5 MHz up to 6.5 MHz
(standard M, N, B/G, I, D/K). The circuit includes two
switchable audio inputs and volume control. With a
supply voltage of 5 V, the U2861B is suitable for TV,
VCR and Multimedia applications.
Features
D
Completely alignment-free
D
PLL demodulator for FM intercarrier sound IF signals
(mono)
D
Very few external components
D
Volume control by DC voltage
D
Supply voltage: 5 V; low power consumption
D
Two audio switches
AF1
in
AF1
out
AF2
in
V
S
v
i,AF1
v
o,AF1
v
i,AF2
C
ref
V
S
1
VCO
12
10
6
Bandgap
reference
7
Sound IF
input
v
i,SIF
Switch1
3
5 k
W
Switch2
8
v
o,AF2
AF2
out
4
GND
2
C
dec
5
V
mute
14
C
dem
13
V
SW1
11
V
SW2
9
V
vol
Decoupling
FM
mute
De-
emphasis
Audio
switch1
Audio
switch2
Volume
control
96 11832
Figure 1. Block diagram
Ordering Information
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taped on reel
TELEFUNKEN Semiconductors
Rev. A1, 20-May-97
1 (11)
Extended Type Number
U2861B – M
U2861B – MFPG3
Package
DIP14
SO14
Remarks
Preliminary Information
TEMIC [ TEMIC SEMICONDUCTORS ]
