1.1.2) Saturating Precision Half-Wave Rectifier Circuit With Voltage Gain
Fig.7-1(b) shows the circuit of a precision rectifier with voltage gain.
This is a noninverting amplifier with the diode included.
The circuit is designed exactly as a noninverting amplifier, except that the current through R1 and R2 should be a minimum of about 100 A to ensure that the diode is operating correctly in the absence of a load current.
A minimum diode current of 500 A is a good design objective.