U4488B Datasheet, PDF (1/9 Pages) TEMIC Semiconductors – Quasi-Split Sound Circuit and AM Demodulator

U4488B
Quasi-Split Sound Circuit and AM Demodulator
Description
The U4488B is an integrated bipolar circuit for full multi-
standard sound IF signal processing in TV/VTR and
Multimedia applications. It supplies AM signals as well
as FM/NICAM sound IF signals and thus allows the de-
sign of a universal sound IF module for various
applications. The U4488B has the same performance like
the U4468B, with the additional feature of a second sym-
metrical IF input.
Features
D 5-V supply voltage; low power consumption
D Gain-controlled 3-stage wideband IF amplifier
D Active carrier generation by FPLL principle
(frequency-phase-locked-loop) for true quadrature
demodulation
Block Diagram
D Complete alignment-free AM demodulator
D Switchable amplitude detector for gain control, which
operates as a peak detector for FM sound and as a
mean level detector for AM sound
D Two symmetrical IF inputs
IF_FM
IF_AM
IF1/IF2
S3
11
1
2
V_S
4
14
REF
IF-Amp
15
IF-Switch
16
Loop
filter
FPLL
5
8
0° _VCO
90°
9
VCO
12
Intercarrier
(FM)
Mean
3
AGC
13
Ordering Information
Extended Type Number
U4488B
6
Peak
level
7
IF AGC
Mean/peak
S1
AM-Det
10
Mute S2
Figure 1. Block diagram
AF(AM)
13789
Package
DIP16
Remarks
TELEFUNKEN Semiconductors
1 (9)
Rev. A2, 15-Jan-98
Preliminary Information