AFEDRI8201

The AFEDRI8201 implements the receive channel analog functions required for intermediate-frequency (IF) sampled AM/FM and HD digital radio receivers. It is designed to be used with TI's DRIx50 digital baseband processor. The AFEDRI8201 is programmed by the DRIx50 for use in AM/FM and HD radio. The AFEDRI8201 oversamples the radio tuner IF output at speeds of up to 80MHz to reduce noise and improve dynamic range. The radio tuner output IF is typically 10.7MHz for AM or FM as well as 450kHz or 455kHz for AM, as desired. The AFEDRI8201 then mixes, filters, and decimates the signal to provide baseband I and Q output signals to the digital baseband processor.

The AFEDRI8201 also includes a general-purpose 12-bit control digital-to-analog converter (DAC) to provide a gain control signal or other analog feedback to the tuner. The DRIx50 digital baseband device writes control register data as well as decimation filter coefficients to the AFEDRI8201 through the industry-standard SPI control interface.

The baseband output signals are transported to the DRIx50 through a general-purpose, high-speed serial interface (TI's Buffered Serial Ports, McBSP). This unit uses 3.3V analog and 1.8V digital power supplies. Typical power dissipation is 490mW. The digital I/O lines can be powered by a 3.3V supply.