MIXED DIGITAL ANALOG SIGNAL-PROCESSING FOR A SINGLE-CHIP 2B1Q U-INTERFACE TRANSCEIVER

Mixed analog—digital signal processing aspects of a 5-V single-chip U-interface 2B1Q transceiver are discussed. Analog signal processing preconditions the signal by reducing jitter-induced echo and nonlinear echo components, and by maximizing the dynamic range utilization of the 13-b A/D converter. The digital signal processor performs the high-pass filtering, precursor equalization, linear echo cancellation, far-end signal equalization, and timing recovery functions. The analog signal preconditioning technique allows the entire DSP section to be designed without a single dedicated multiplier. The U-interface transceiver has been realized in a 1.5-μm double-metal CMOS process, resulting in a circuit area of 77 mm2. Total power consumption is 300 mW. © 1990 IEEE