U4468B
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
- plete 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 processing 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 module for various applications.
Quasi-split Sound Circuit and AM Demodulator IC U4468B
Figure 1. Block Diagram
VS 4 14 REF IF-amp
Loop filter 5 FPLL 05 905 VCO 8 9 VCO
IFFM 2 1 IFAM
12 Intercarrier (FM)
Mean 3 AGC Peak level 13 IF AGC Mean/peak 7 S1 Mute AM-det 10 S2 6 AF (AM)
Rev. 4777A- TVVCR- 01/04
Circuit Description
IF Amplifier and AGC
The symmetrical IF input...
