A Single-Chip VLSI Echo Canceler

A single-chip VLSI (very large-scale integration) echo canceler has been fabricated in NMOS(N-channel metal-oxide semiconductor). The canceler has a 128-tap (16-ms) delay line and a white-noise convergence rate of 70 dB/s. The chip measures 313 by 356 mils and contains 35,000 devices.