Monolithic analog adaptive equalizer integrated circuit for wide-band digital communication networks

This equaliser is presented with particular emphasis on architecture and performance. To reduce the size, cost, and power dissipation, and to improve the operation speed and performance, this equalizer IC employs many techniques such as all analog signal processing with parallel updating the weights and eliminating the offset according to the least mean-square algorithm, MOS VLSI fabrication process and switched capacitor technique. As the key building blocks, low- and high-speed MOS operational amplifiers and four-quadrant analog multipliers are specially developed. The 16 mm/SUP 2/ chip providing 5 taps operates on ±5 and 10 V power supplies with power dissipation of 570 mW. The maximum data rate is more than 200 kHz. For the linear adaptive equalizer configuration operating at a data rate of 100 kHz, the residual RMS distortion and convergence time are measured to be -40 dB and about 2 ms (200 iterations), respectively, when a binary signal with an initial RMS distortion of 40 percent (-7.96 dB) is applied.