TEA6848H

General description

The TEA6848H is a single IC with car radio tuner for AM, FM and Weather Band (WB) intended for microcontroller tuning with the I²C-bus. It provides the following functions:

• AM double conversion receiver for LW, MW and SW (31 m, 41 m and 49 m bands) with IF1 = 10.7 MHz and IF2 = 450 kHz
• FM double conversion receiver with integrated image rejection for IF1 and for IF2 capable of selecting US FM, US weather, Europe FM, East Europe FM and Japan FM bands; fully integrated dynamic selectivity at 450 kHz FM IF2; FM demodulator with dynamic threshold extension; centre frequency alignment of IF2 selectivity via the I²C-bus
• The tuning system includes VCO, crystal oscillator and PLL synthesizer on one chip.

Features

• FM mixer 1 for conversion of FM RF (65 to 108 MHz and US weather band) to IF of 10.7 MHz; the mixer provides inherent image rejection; for European and US FM band/WB (weather band) the mixer is driven with a 'high' injection Local Oscillator (LO); in Japan FM band and East Europe FM band the mixer is driven with a 'low' injection LO
• AM mixer 1 for conversion of AM RF to AM IF1 of 10.7 MHz
• LC tuner oscillator providing mixer frequencies for FM mixer and AM mixer 1
• AM mixer 2 for conversion of AM IF1 to AM IF2 of 450 kHz
• Crystal oscillator providing mixer frequencies for AM mixer 2 and FM mixer 2 and reference for synthesizer PLL, IF count, timing for Radio Data System (RDS) update and reference frequency for car audio signal processor ICs
• Fast synthesizer PLL tuning system with local control for inaudible RDS updating
• Timing function for RDS update algorithm and control signal output for car audio signal processor ICs (TEA688x, SAA77xx, TEF689x)
• Digital alignment circuit for bus controlled matching of oscillator tuning voltage to FM antenna tank circuit tuning voltage
• AGC PIN diode drive circuit for FM RF AGC; AGC detection at FM mixer input; the AGC PIN diode drive can be activated by the I²C-bus as a local function for search tuning; AGC threshold is a programmable and keyed function switchable via the I²C-bus
• FM IF linear amplifier with high dynamic input range
• FM mixer 2 for conversion of FM IF1 to FM IF2 of 450 kHz with inherent image rejection
• Fully integrated dynamic selectivity and FM demodulator at IF2; improved sensitivity with dynamic threshold extension; centre frequency of IF2 selectivity alignment via the I²C-bus
• Level detector for AM and FM with temperature compensated output voltage; starting point and slope of level output is programmable via the I²C-bus
• AM cascode AGC stage and RF PIN diode drive circuit; AGC threshold detection at AM mixer 1 and IF2 AGC input; threshold for detection at mixer 1 input is programmable via the I²C-bus
• AM IF2 AGC and demodulator
• AM AF output switchable to provide AM IF2 for AM stereo decoder
• AM noise blanker with detection at IF1 and blanking at AM IF2
• Software controlled flag output
• Buffer output for weather band flag
• Adjacent channel detector, modulation detector and frequency offset for instantaneous bandwidth control of the integrated filter
• Flag and voltage output indicating the actual bandwidth
• I²C-bus alignment of centre frequency and gain variation as functions of bandwidth of the IF2 filter and centre frequency of the offset detector.

Products/packages

All type numbers in the table below are discontinued. See the table Discontinued information for more information.

Quality/reliability/chemical content

All type numbers in the table below are discontinued. See the table Discontinued information for more information.

Quality and reliability disclaimer

Discontinued information

Design support

Application Notes

AN00001_2; TEA6848H a nice radio with circumstantial controlled selectivity (2002-11-19)

AN99040_2; TEA684x family a NICE radio for New In Car Entertainment (2004-11-01)

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Disclaimers

• General product disclaimer
• Quality and reliability disclaimer