DESCRIPTION
The VES1820X is a single chip channel receiver for 16, 32, 64, 128 and 256-QAM modulated signals. The device interfaces directly to the IF signal, which is sampled by a 9-bit AD converter.
The VES1820X performs the clock and the carrier recovery functions. The digital loop filters for both clock and carrier recovery are programmable in order to optimize their characteristics according to the current application.

FEATURES
• 16/32/64/128/256 QAM demodulator (DVB-C compatible : ETS 300-429).
• On chip 9-bit ADC.
• On chip PLL for crystal frequency multiplication.
• Digital down conversion.
• Half Nyquist filters (roll off = 15 %).
• Automatic gain control PWM output (AGC).
• Symbol timing recovery, with programmable second order loop filter.
• Variable symbol rate capability from SACLK/64 to SACLK/4 (SACLK max = 36 MHz)
• Programmable anti-aliasing filters.
• Full digital carrier recovery loop.
• Carrier acquisition range up to 8 % of symbol rate.
• Integrated adaptative equalizer (Linear Transversal Equalizer or Decision Feedback Equalizer).
• On chip FEC decoder (Deinterleaver & RS decoder), full DVB-C compliant.
• DVB compatible differential decoding and mapping.
• Parallel or serial transport stream interface.
• I2C bus interface, for easy control.
• CMOS 0.35µm technology.

APPLICATIONS
• DVB-C fully compatible.
• Digital data transmission using QAM modulations.
• Cable demodulation.
• Cable modems
• MMDS (ETS 300-429).