GENERAL DESCRIPTION
Separate symmetrical IF inputs for FM or AM sound.
Gain controlled wideband IF amplifier, input select switch. AGC generation due to peak sync for FM or mean signal level for AM. Reference amplifier for the regeneration of the vision carrier. Optimized limiting amplifier for AM suppression in the regenerated vision carrier signal and 90° phase shifter.
Intercarrier mixer for FM sound, output with low-pass filter. Separate signal processing for 5.5 and 5.74 MHz intercarriers. Wide supply voltage range, only 300 mW power dissipation at 5 V.

FEATURES
• Quasi-split sound processor for all standards e. g. B/G (FM sound) and L (AM sound)
• Reducing of spurious video signals by tracking function and AFC for the vision carrier reference circuit; (recommended for NICAM)
• Automatic muting of the AF2 signal (at B/G) by the input level
• AM signal processing for L standard and switching over the audio signal
• Stereo matrix correction
• Layout-compatible with TDA3856 (24 pins) and TDA3857 (20 pins)