GENERAL DESCRIPTION
The circuits incorporate two FM demodulator systems to perform the demodulator functions required in a dual sound carrier TV system for demodulating the sound carriers. The difference between TDA2555 and TDA2557 is the number of stages of the limiting amplifier.

• Eight (TDA2555) or five (TDA2557) stage limiting amplifier
• Quadrature demodulator for FM detection
• De-emphasis stage
• Output amplifier
• Mute function for each FM demodulator