TEF6903AH
1. General description
The TEF6903A is a single-chip car radio integrated circuit with FM/AM tuner, stereo
decoder, weak signal processing and audio processing. Radio Data System (RDS)/Radio
Broadcast Data System (RBDS) demodulator for radio data reception is included.
FM tuner with double conversion to IF1 = 10.7 MHz and IF2 = 450 kHz with integrated
image rejection for both IF1 and IF2; integrated channel filter with variable bandwidth
control; capable of US FM, Europe FM, Japan FM and Eastern Europe FM. AM tuner with
double conversion to IF1 = 10.7 MHz and IF2 = 450 kHz; capable of Long Wave (LW),
Medium Wave (MW) and full range Short Wave (SW) (11 m to 120 m bands).
Multiplex (MPX) stereo decoder, ignition noise blanker and extensive weak signal
processing.
Audio processing with flexible source selection, volume, balance, fader, input gain control
and inaudible tuning mute. The application of an external processor is possible. Integrated
audio filters for bass and treble and loudness control function.
The device can be controlled via the fast-mode I2C-bus (400 kHz) and includes
autonomous tuning functions for easy control without microcontroller timing. No manual
alignments are required.
2. Features
n FM Radio Frequency (RF) front-end with large dynamic range
n Integrated FM channel filter with controlled bandwidth
n Fully integrated FM demodulator
n Fully integrated stereo decoder with high immunity for birdy noise
n FM noise blanker with adaptive detection at MPX and level
n Signal quality detection: level, AM wideband, frequency deviation, ultrasonic
noise/adjacent channel
n FM weak signal processing: stereo blend, high cut control and soft mute
n AM RF Automatic Gain Control (AGC) circuit for external cascode AGC and Positive
Intrinsic Negative (PIN) diode AGC
n Dual AM noise blanking system
n AM weak signal processing: high cut control and soft mute
n Low phase noise local oscillator
n In-lock detection for optimized adaptive Phase-Locked Loop (PLL) tuning speed
n Crystal oscillator reference with low harmonics
n Inaudible soft slope tuning mute for AM and FM
n Sequential state machine supporting each tuning action
