GENERAL DESCRIPTION

The TDA10085 is a single-chip channel receiver for satellite television reception matching both DSS and DVB-S standards. The device contains a dual 6-bit flash ADC, variable rate BPSK/QPSK coherent demodulator and forward error correction functions. The ADC interfaces directly with I and Q analog baseband signals.

FEATURES

? DSS and DVB-S compliant single chip demodulator and forward error correction

? Dual 6-bit Analog-to-Digital Converter (ADC) on-chip

? PLL that allows using a low-cost crystal (typically 4 MHz)

? DiSEqC 1.X from 1 to 8 byte-long sequences with modulated or unmodulated output

? DSS dish control

? Digital cancellation of ADC offset

? Simultaneous parallel and serial output interfaces

? Variable rate BPSK/QPSK coherent demodulator

? Modulation rate variable from 1 to 49 Mbauds

? Automatic gain control output

? Digital symbol timing recovery:

– Acquisition range up to 960 ppm

? Carrier offset cancellation up to one half of the sampling frequency

? Digital carrier recovery:

– Acquisition range up to 12 of the symbol rate

? Half-Nyquist filters: roll-off = 0.35 for DVB and 0.2 for DSS

? Interpolating and anti-aliasing filters to handle variable symbol rates

? Channel quality estimation

? Spectral inversion ambiguity resolution

? Viterbi decoder:

– Supported rates from 1/2 to 8/9

– Constraint length K = 7 with G1 = 1718 and G2 = 1338

– Viterbi output BER measurement

– Automatic code rate search within 1/2, 2/3 and 6/7 in DSS mode

– Automatic code rate search within 1/2, 2/3, 3/4, 5/6 and 7/8 in DVB-S mode

? Convolutional de-interleaver and Reed Solomon decoder according to DVB and DSS specifications

? Automatic frame synchronization

? Selectable DVB-S descrambling

? I2C-bus interface

? 64-pin TQFP package

? CMOS technology (0.2 μm, 1.8 V to 3.3 V)

APPLICATIONS

? DVB-S receivers (ETS 300-421)

? DSS receivers.