QPSK/BPSK DIGITAL DEMODULATOR

The MC92303 is a coherent digital demodulator for QPSK and BPSK modulated signals utilized in Digital-TV applications according to the EBU defined DVB transmission standard for satellite Set-Top systems or similar. The MC92303 contains all the functionality required to lock onto signals with frequency offsets as large as the baud rate and extract the desired signal from a frequency band with adjacent channel interference and other undesirable signals.

Feature Summary

? DVB compliant QPSK/BPSK Coherent Demodulator

? Variable Modulation Rate up to 30 MBaud to work with all present European DVB Channels

? Selectable Input Format (Offset Binary/2’s Complement)

? DC Offset Removal, I/Q-swapping and Input Format Selection in one block

? Decimation Filters for Oversampling Ratios of 2/T, 3/T, 4/T, 6/T, 8/T, 12/T and 16/T

? Half Nyquist Baseband Filters (α=0.35)

? Internal Numerically Controlled Oscillator (NCO)

? Automatic Gain Control (AGC) provided to analog front-end

? Automatic Frequency Control (AFC) to ±Rs (Symbol Rate)

? Clock Synchronization with 1-Bit Σ?-Converter Output for ADC control

? Programmable Second Order Loop Filters for Carrier Recovery and AGC

? 3-bit Soft Decision output per Symbol with selectable format (Offset Binary/2’s Complement/Sign Magnitude)

? Programmable Sampling Rates of the Digital Sigma-Delta Converters

? < 0.5 dB Implementation Loss from theory

? I2C Programmable Interface

? 0.5μ CMOS Process at 3.3V