TEF6721HL

· 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.

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.