2) Precision Full-Wave Rectifiers (Absolute Value Circuit) 2.2) High Input Impedance Full-Wave Precision Rectifier
A precision rectifier that uses a noninverting amplifier configuration to present a high input impedance to the signal is shown in Fig.7-5.
Op-amp A1 together with resistors R3 and R4 constitutes a noninverting amplifier, as does A2, R5 and R6.
However, diodes D1 and D2 also affect the operation of the circuit.