TDA7540N AM/FM car radio tuner IC with stereo decoder and intelligent selectivity system (ISS) Features FM-part RF AGC generation by RF and IF detection I/Q mixer for 1st FM IF 10.7MHz with image LQFP80 rejection Mixer for 2nd IF 450kHz Additional features Internal 450KHz bandpass filter with bandwidth control by ISS VCO for world tuning range Fully integrated FM-demodulator with spike High performance fast PLL for RDS-System cancellation IF counter for FM and AM with search stop signal AM-part Quality detector for level, deviation, adjacent Wide and narrow AGC generation channel and multipath Mixer for 1st IF 10.7MHz, AM upconversion ISS (intelligent selectivity system) for Mixer for 2nd IF 450kHz, AM downconversion cancellation of adjacent channel and noise influences Integrated AM-demodulator Adjacent channel mute AM IF- and audio noise blanking Fully electronic alignment Stereodecoder 2 All functions I C-Bus controlled PLL with adjustment free, fully integrated VCO Automatic pilot dependent mono/stereo Description switching The TDA7540N is a high performance tuner Programmable ROLL-OFF compensation circuit for AM/FM car radio. It contains mixer, IF High cut and stereo blend-characteristics amplifier, demodulator for AM and FM, programmable stereodecoder, quality detection, ISS filter and PLL synthesizer with IF counter on a single chip. Dedicated RDS-mute Use of BICMOS technology allows the Internal noise blanker with several threshold implementation of several tuning functions and a controls minimum of external components. Table 1. Device summary Order code Temp range, CPackage Packing TDA7540N -40 to 85C LQFP80 (14x14x1.4mm) Tube TDA7540NTR -40 to 85C LQFP80 (14x14x1.4mm) Tape and reel September 2013 Rev 2 1/76 www.st.com 1Contents TDA7540N Contents 1 Block diagram 7 2 Pins description and connection diagrams 8 2.1 LQFP80 pins connection diagram . 8 2.2 Pin description 8 3 Electrical specifications . 11 3.1 Absolute maximum ratings 11 3.2 Thermal data 11 3.3 Electrical characteristics 11 3.3.1 Globals 11 3.3.2 FM section . 12 3.3.3 AM section . 17 3.3.4 Stereodecoder 19 3.3.5 PLL Section 25 4 Functional description 27 4.1 FM section 27 4.1.1 Mixer1, AGC and 1.IF 27 4.1.2 Mixer2, limiter and demodulator . 27 4.1.3 Quality detection and ISS . 27 4.1.4 Soft mute control 28 4.2 AM section 29 4.3 Stereodecoder . 29 4.3.1 Decoder . 29 4.3.2 Functional description of the noise blanker 32 4.3.3 Functional description of the multipath-detector 33 4.3.4 Quality detector . 33 4.3.5 AFS control and stereo decoder mute 34 4.4 PLL and IF counter section . 34 4.4.1 PLL frequency synthesizer block 34 4.4.2 IF counter block . 35 2 4.5 I C-Bus interface . 37 2/76