CX24123 Datasheet | Conexant Systems

Digital Set-top Box Solutions Satellite CX24123 Demodulator and FEC Decoder Low-power QPSK demodulator for worldwide satellite set-top box applications Conexant’s broadband munications portfolio includes a prehensive suite of semiconductor solutions that enable the digital home and information network. The CX24123 is a DVB, DSS, and DCII pliant demodulator and Forward Error Correction (FEC) decoder. When bined with a satellite tuner, such as the CX24109 tuner, the CX24123 provides a plete broadband satellite front-end solution capable of operating from 1 to 45 Msps. The CX24123 is the ideal solution for a wide variety of applications in digital satellite set-top box, personal puter receivers and residential gateways. This Di SEq C™ 2.x pliant demodulator enables two-way munication between the set-top box and peripheral satellite equipment such as Low Noise Block Converters (LNB) and switches. Providing digital derotation, digital filtering, equalization, and Viterbi/Reed Solomon FEC, the CX24123 provides many advanced Features that enhance overall system performance. The CX24123 automatically corrects for external quadrature gain/phase imbalances and for DC offsets. Input signal level variations (e.g., due to rain fade) are pensated by automatic gain control CX24123 Distinguishing Features - Symbol rates: 1 to 45 Msps - Automatic acquisition - Low-power design - Internal SNR and BER monitors - Di SEq C Level 2.x patible ™ w w (AGC). Frequency offsets due to inexpensive consumer LNBs are corrected by a robust Carrier-Tracking Loop. A unique feature of the CX24123 is an automatic acquisition algorithm that searches and acquires the carrier within a ± 10 MHz range during initial acquisition and performs a smart search to reacquire the carrier during fade conditions. The CX24123 has integrated signal-to-noise Ratio (SNR) and Bit Error Rate (BER) monitors for basic channel performance measurements, which saves time and test equipment...