TEF6721HL: Car radio tuner front-end for digital IF ARCHIVED

Overview

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The TEF6721HL is a single chip car radio tuner for AM, FM standard, FM In-Band On-Channel Digital Audio Broadcast (IBOC DAB) and weather band providing combined AM and FM gain controlled differential Intermediate Frequency (IF) output for the SAF7730H including the following functions:

AM up-conversion tuner to an IF frequency of 10.7 MHz for Long Wave (LW)/Medium Wave (MW)/Short Wave (SW) (31 m, 41 m and 49 m bands)
FM single conversion tuner to an IF frequency of 10.7 MHz with integrated image rejection for US FM, Europe FM, Japan FM, East Europe FM and weather band reception; all bands can be selected using high side or low side Local Oscillator (LO) injection
Tuning system includes Voltage-Controlled Oscillator (VCO), crystal oscillator and Phase-Locked Loop (PLL) synthesizer on one chip.

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Features

FM mixer for conversion of FM Radio Frequency (RF) (64 MHz to 108 MHz and US weather band) to an IF of 10.7 MHz; the mixer provides inherent image rejection and can be switched from low injection to high injection Local Oscillator (LO) via the I²C-bus; two different mixer conversion gains can be selected via the I²C-bus
Automatic Gain Control (AGC) PIN diode drive circuit for FM RF AGC; AGC detection at FM mixer input and IF AGC amplifier input; AGC threshold for detection at FM mixer input is a programmable and keyed function switchable via the I²C-bus; the AGC PIN diode drive can be activated via the I²C-bus as a local function for search tuning; in AM mode the AGC PIN diode drive can be activated via the I²C-bus if required
Digital alignment circuit for bus controlled matching of oscillator tuning voltage to FM antenna tank circuit tuning voltage
Buffer output for weather band flag
Combined AM and FM IF AGC amplifier with high dynamic input range; one of the four gain settings is selected automatically via two control signals from IF Digital Signal Processor (DSP); combined differential AM and FM IF output signal to analog-to-digital converter of IF DSP
AM mixer for conversion of AM RF to AM IF 10.7 MHz
AM RF PIN diode drive circuit and RF Junction Field Effect Transistor (JFET) conductance control by AGC cascode drive circuit; AGC threshold detection at AM mixer and IF AGC input; threshold for detection at AM mixer is programmable via the I²C-bus
AM and FM RF AGC monitor output intended for gain control of active antennas
Inductor Capacitor (LC) tuner oscillator providing mixer frequencies for FM and AM mixers
Crystal oscillator providing reference frequencies for synthesizer PLL and timing for Alternative Frequency (AF) updating
Optional crystal oscillator frequency pulling possibility via I²C-bus
Fast synthesizer PLL tuning system with local control for inaudible AF updating
Timing function for AF updating algorithm and control signal output for interfacing with IF DSP
Three hardware programmable I2C-bus addresses; pin BUSENABLE; two software controlled flag outputs
Several test modes for fast Integrated Circuit (IC) tests.

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Features

Outline 3d SOT314-2

Outline 3d SOT314-2

Outline 3d SOT314-2

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