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So I used a voltage follower with an input of a sine wave signal (positive and negative cycle) . The output was half wave signal which is what I wanted. Why do people use half wave precision rectifier signal over a voltage follower. It seems a lot easier to just use a voltage follower. I am using a single power supply with Vcc- to GND.

Which is better for half wave signal rectification, a voltage follower or half wave rectifier?

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Voltage Spike
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Sam
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1 Answers1

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Why do people use half wave precision rectifier signal over a voltage follower.

In most applications using only a voltage follower and use the rail to do the clipping will leave common mode issues (the output may not approach zero or may distort or even hit the other rail). Below is an example, the blue trace is the output of the voltage follower, when the input goes negative, the output hits the positive rail.

Vout1 is the precision half wave rectifier (with the same opamp) (I also inverted vout1 which is the output of the precision half wave rectifier so it doesn't lie on top of the other trace). There are rail to rail input and output amplifiers that could approach the performance of the precision half wave rectifier.

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Voltage Spike
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  • Interesting. I will take the common mode issue into consideration. As you have said, I might be using a rail to rail opamp that is is capable of preforming close to the precision rectifier. I was able to get a good half wave signal using TSH82 opamp. – Sam Aug 12 '21 at 19:41