Four-stage circuit architecture for detecting pulsed signals

摘要

An electrical circuit includes a photodiode that receives a light signal from a light source and generates a photocurrent signal, a trans-impedance amplifier that amplifies the photocurrent signal and generates a low noise signal, and a high pass filter that converts the low noise signal into an alternating current (AC) signal having a positive amplitude, a negative amplitude, and a zero cross-over point between the positive amplitude and the negative amplitude. The electrical circuit also includes a positive integrating amplifier that receives the positive amplitude of the AC signal and generates a positive integrated value over an integration period, and a negative integrating amplifier that receives the negative amplitude of the AC signal and generates a negative integrated value over the integration period. The electrical circuit further includes at least one analog-to-digital converter that receives the positive and negative integrated values.

主权项

1. An electrical circuit, comprising:
a photodiode that receives a light signal from a light source and generates a photocurrent signal; a first stage comprising a trans-impedance amplifier that amplifies the photocurrent signal and generates a low noise signal; a second stage comprising a high pass filter that converts the low noise signal into an alternating current (AC) signal having a positive amplitude, a negative amplitude, and a zero cross-over point between the positive amplitude and the negative amplitude; a third stage comprising:
a positive integrating amplifier that receives the positive amplitude of the AC signal and generates a positive integrated value over an integration period; anda negative integrating amplifier that receives the negative amplitude of the AC signal and generates a negative integrated value over the integration period; and a fourth stage comprising at least an analog-to-digital converter (ADC) that receives the positive and negative integrated values.