GENERAL DESCRIPTION
1.1. Introduction SPHE6613A is the a single-chip QPSK/8PSK satellite demodulator, which is compliant with DVB-S (as defined in ETS 300 421 specification) and DVB-S2 (as defined in ETS 302 307 specification). It can support different symbol rates from 1 MHz to 45 MHz. The device integrates dual high performance 8-bit A/D converters. The sampling rates can be generated from different clock sources: either. It may be from a 27 MHz crystal or anthe external clock (4/10/10.11/15/16 MHz from tuner). and cChanginge the setting ofin the relative register can to achieve the target sampling rate. The QPSK/8PSK demodulator can do the channel blind search and confirmed the channel by the lock criteria. Inner channel decoders includes Viterbi decoder and LDPC decoder. Viterbi decoder can detect the code rate automatically without any extra information. LDPC decoder needs the code rate information from the previous processing to complete the decoding. BesidesExcept that, the FEC part can provide users many helpful information including pre-Viterbi/pre-LDPC BER and post-Viterbi/post-LDPC BER.
