Fig 1 shows a high-speed, full-wave rectifier-or absolute-value circuit-that uses a high-speed clamping amplifier, IC2. This circuit is faster and performs better than rectifiers employing diodes in their amplifiers’ feedback paths. These diode-based circuits have limitations at lower signal-input levels and higher bandwidths. These limitations show themselves most clearly as crossover distortion. This circuit cleanly corrects a 20-MHz, 600-mV p-p input sine wave (50(ohm) back-terminated). The circuit employs IC2′s clamping action while IC1 and IC3 function as a buffer….Link