U4454B
Quasi-Split-Sound Processing and AM-Demodulator
Description
The U4454B quasi-split-sound processor is a bipolar
integrated circuit for all FM-TV standards and NICAM
sound systems. For FM/NICAM the IC operates as
QSS-mixer. In case of AM sound the circuit can be used
as AM demodulator.
Features
D
PLL intercarrier-mixer for all FM standards
(incl. NICAM sound system)
D
High input sensitivity
D
Wide supply voltage range (6.8 V up to 13 V)
D
Low power consumption
D
ESD protection
Case:
16-pin DIL plastic
D
High grade signal processing for FM/NICAM
sound systems
D
Also suitable as AM-demodulator
D
Gain controlled wideband amplifier
D
AGC operates as a peak- and mean-level detector
Block Diagram
VCO Tank
Loop filter
93 7653
12
Lock
detector
16
IF Input
1
Video
11
8
9
VCO
90°
0°
Interference
rejection
6
Output
Overload
detector
14
3
NC
+/–
Lock
detector
AGC
+V
S
2
NC
5
IF AGC
4
15
10
7
Average
13
Figure 1.
TELEFUNKEN Semiconductors
Rev. A1, 23-Feb-96
1 (7)
Preliminary Information
TEMIC [ TEMIC SEMICONDUCTORS ]
