Active Rectifier Calculator

Active Rectifier Calculator. An active rectifier uses op-amps instead of diodes to convert AC voltage into DC with minimal voltage drop — making it useful for low-voltage precision circuits. Enter your input RMS voltage, frequency, load resistance, filter capacitor, and op-amp supply voltage, then select a half-wave or full-wave configuration to calculate the output DC voltage. Secondary outputs include output current, ripple factor, rectification efficiency, and peak input voltage. Also try the Integrator Circuit Calculator.

Active Rectifier Calculator inputs
V
Hz
Ω
μF
V

Results

Output DC Voltage

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Output Current

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Ripple Factor

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Rectification Efficiency

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Peak Input Voltage

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What is an active rectifier circuit?

An active rectifier uses operational amplifiers to overcome the voltage drop limitations of passive diode rectifiers, providing precise rectification with minimal voltage loss and improved performance. See also our Inverting Amplifier Calculator.

How does an active rectifier differ from a bridge rectifier?

Active rectifiers use op-amps to eliminate diode voltage drops (typically 0.7V), allowing rectification of small signals and providing better efficiency and accuracy compared to traditional bridge rectifiers.

What are the applications of active rectifier circuits?

Active rectifiers are used in precision measurement instruments, low-voltage signal processing, audio applications, and anywhere minimal voltage drop and high accuracy are required.

How do I calculate the ripple factor of an active rectifier?

Ripple factor is calculated as the ratio of RMS ripple voltage to DC output voltage. For capacitive filtering, it depends on the load resistance, capacitance, and switching frequency.

What op-amp specifications are important for active rectifiers?

Key specifications include high slew rate, wide bandwidth, low offset voltage, and sufficient output current capability. The supply voltage should exceed the expected peak input voltage.

Can active rectifiers handle high-frequency signals?

Yes, active rectifiers can handle higher frequencies better than passive rectifiers, limited primarily by the op-amp's bandwidth and slew rate specifications.

What is the efficiency of an active rectifier?

Active rectifiers typically achieve 80-95% efficiency depending on the configuration, load conditions, and op-amp characteristics, generally higher than passive rectifiers for low-voltage applications. You might also find our High Threshold Voltage (VTH) — Comparator useful.