U4468B Datasheet, PDF (1/11 Pages) ATMEL Corporation – Quasi-split Sound Circuit and AM Demodulator IC

Features
• 5-V Supply Voltage
• Gain-controlled 3-stage Wide-band IF Amplifier
• Active Carrier Generation by FPLL Principle (Frequency-Phase-Locked-Loop) for True
Quadrature Demodulation
• Complete Alignment-free AM Demodulator
• Switchable Amplitude Detector for Gain Control, which Operates as a Peak Detector for
FM Sound and as a Mean Level Detector for AM Sound
Description
The U4468B is an integrated bipolar circuit for full multistandard sound IF signal pro-
cessing in TV/VTR and multimedia applications. It supplies AM signals as well as
FM/NICAM sound IF signals and thus allows the design of a universal sound IF mod-
ule for various applications.
Quasi-split
Sound Circuit
and AM
Demodulator IC
Figure 1. Block Diagram
U4468B
IF_FM
IF_AM
V_S
4
14
2 ^IF-amp
1
REF
Loop
filter
FPLL
5
8
05
905 ^VCO ₉
VCO
12
Intercarrier
(FM)
3
AGC
Mean
Peak
level
13
7
IF AGC
Mean/peak
S₁
AM-det
6
AF (AM)
10
Mute S₂
Rev. 4777A–TVVCR–01/04