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Optical Microphone Schematic | by scanlime
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Optical Microphone Schematic

1. IR LED is driven at DC (No modulation in this version)

2. A high-gain transimpedance amplifier converts the photocurrent to a voltage.

3. High-pass filter to strip out the DC component and get the audio only

4. Gain stage: non-inverting amplifier with 1/2 Vcc reference voltage

5. Another high-pass capacitor, to remove the DC reference voltage.


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Uploaded on February 3, 2010