Description
The TDA7541 is a high performance tuner circuit with stereo decoder for AM/FM car radio. It contains a mixer, IF amplifier, demodulator for AM and FM, stereo decoder, quality detection, ISS filter and PLL synthesizer with IF counter on a single chip. Use of BICMOS technology allows the implementation of several tuning functions and a minimum of external components.

FEATUREs
■ FM part
   – AGC generation by RF and IF detection
   – I/Q mixer for 1st IF 10.7MHz with image rejection
   – Mixer for 2nd IF 450kHz
   – Internal 450kHz band pass filter with bandwidth control by ISS
   – Fully integrated FM demodulator with noise cancellation
■ AM part
   – Wide and narrow AGC generation
   – Mixer for 1st IF 10.7MHz, AM upconversion
   – Mixer for 2nd IF 450kHz
   – Integrated AM-demodulator
   – AM IF noise blanking
■ Stereo decoder
   – PLL with adjustment free, fully integrated VCO
   – Automatic pilot dependent MONO/STEREO switching
   – Programmable ROLL-OFF compensation
   – High cut and stereo blend-characteristics programmable
   – Dedicated RDS mute
   – Audio noise blanker
■ Additional features
   – VCO for world tuning range
   – High performance fast PLL for RDS System
   – IF counter for FM and AM with search stop signal
   – Quality detector for level, deviation, adjacent channel and multipath
   – ISS (Intelligent selectivity system) for cancellation of adjacent channel and noise influences
   – Adjacent channel mute
   – Fully electronic alignment
   – Independend weather band input
   – All functions I2C bus controlled