器件名称: U2861B-MFPG3
功能描述: Mono FM Sound Demodulator for TV Systems
文件大小: 263.07KB 共11页
简 介:U2861B
Mono FM Sound Demodulator for TV Systems
Description
The U2861B is an alignment-free FM sound IF demodulator 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
AF1in
AF1out
AF2in
VS
vi,AF1
vo,AF1
vi,AF2
Cref
VS
1 VCO
12
10
6 Bandgap reference
7
Sound IF input vi,SIF
Switch1 3 5 kW
Switch2 8 vo,AF2 AF2out
4
GND
2
Cdec
5
Vmute
14
Cdem
13
VSW1
11
VSW2
9
Vvol
Decoupling
FM mute
Deemphasis
Audio switch1
Audio switch2
Volume control
96 11832
Figure 1. Block diagram
Extended Type Number U2861B – M U2861B – MFPG3 Package DIP14 SO14 Remarks taped on reel TELEFUNKEN Semiconductors Rev. A1, 20-May-97 1 (11)
Ordering Information
Preliminary Information
U2861B
Circuit Description
Sound IF Limiter Amplifier
The intercarrier signal coming from the sound filter is fed to a 7-stage limiter amplifier. This guarantees high input sensitivity and excellent AM suppression.
Audio Switch 1
The first audio switch (Pin 13) has inputs for the demodulated FM signal and the external AF1 signal from Pin 1. For multistandard purposes, it is ……
