AFE8201

The AFE8201 consists of a general-purpose, 80MSPS, 12-bit analog-to-digital converter (ADC), a digital downconverter (DDC), and user-programmable digital filters. It is designed to sample narrowband (2.5MHz or less) IF signals and digitally mix, filter, and decimate the signals to baseband.

The DDC consists of a digital quadrature mixer followed by a CIC decimation filter and FIR filters. The mixer frequency and initial phase are independently programmed by 32-bit control words. After the CIC filter, the internal I and Q signals are passed on to the first FIR filter, which can implement even, odd, halfband, and arbitrary impulse responses with up to 62 taps using 16-bit coefficients. Following the first FIR filter are two parallel FIR filters that can be used to provide two output streams or interleaved to form one extended filter with up to 262 taps.

The AFE8201 also contains a 12-bit general-purpose auxiliary digital-to-analog converter (DAC) for applications such as AGC amplifier control. Control register data as well as decimation filter coefficients are written to the AFE8201 through the industry-standard SPI control interface.

The baseband output signals are transported through a generalpurpose, high-speed serial interface that is compatible with TI C5x/C6x DSP family buffered serial ports (McBSP).