TDA7421

® TDA7421 AM/FM TUNER FOR CAR RADIO AND Hi-Fi APPLICATIONS FRONT-END FOR AM/FM RECEIVERS UP-CONVERSION ARCHITECTURE FOR AM HIGH SPEED PLL WITH INLOCK DETECTOR FOR OPTIMIZED RDS APPLICATIONS SINGLE FREQUENCY REFERENCE FOR AM/FM AM/FM STATION DETECTOR µP-CONTROLLED COMPENSATION OF EXTERNAL COMPONENTS SPREAD ADJUSTABLE AUDIO MUTE FULLY PROGRAMMABLE BY I2C BUS ADVANCED BICMOS TECHNOLOGY GENERAL DESCRIPTION The TDA7421 is a high performance tuner circuit that integrates AM/FM sections, IF counter and PLL synthesizer on a single chip. Use of BICMOS technology allows the implementation of tuning functions with a minimum of external components. Value spread of external components can be fully PINS CONNECTION AM AGC1 RF AMP FM IF AMP1 OUT FM IF AMP1 IN + FM IF AMP2 IN + FM IF AMP1 IN AM AGC1 PIN TQFP64 ORDERING NUMBER: TDA7421 compensated by means of on-chip electrical adjustment controlled by external µP. The Automatic Gain Control (AGC) operates on different sensitivities and bandwidths in order to improve sensitivity and dynamic range. I2C bus allows to control selected functions of the tuner (AGC and amplifiers gain, PLL and counters operation modes). AM AGC1 TC MIX OUT + MIX OUT - 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 AM MIX1 IN AM MIX1 IN + FM MIX IN FM MIX IN + FM RF AGC IN FM AGC OUT RF GND VCO B VCO E OSC GND XTAL D XTAL G OSC VCC FM ANT ADJ FM RF ADJ PLL VCC 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 DIG GND IFC S...