LM3900 Clamp Circuit for Harmonic Generation

A quick investigation into a LM3900 circuit for half-wave rectification for frequency doubling. A step along the way is a precision clamp circuit that will ultimately offset the gain of a DC amplifier. The circuit below provides a DC clamp for approximately half of of an input triangle waveform, which was normalized to a voltage swing of 6V to 3V, based on the +6V LM3900 reference voltage circuit.

Development of LM3900 Clamp Circuit

I/O with R3=390kΩ

Clamp circuit modified to use R3 = 464kΩ, 1% + 499kΩ, 1% (963kΩ equivalent)

Visual alignment of Vo to Vi -- clamp set for slightly more than 1/2 of input with R3 = 963kΩ

Tighter measurement of clamped Vo.

Looking in close to how the clamp behaves at bottom.

Zoom-in and signal averaging of clamp near GND output of LM3900  (N=16)



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