Differential photodiode integrator circuit for absorbance measurements

摘要

The invention relates to a photodetector measurement circuit, a detection system and a method for measuring a light intensity. An example photodetector measurement circuit comprises a photodetector (102) that receives a light and generates a photodetector current indicative of the light intensity. The measurement circuit includes a first integrator (104) coupled along a first signal path to the photodetector (102) to generate a first voltage signal at a first integrator output indicative of an integral of the photodetector current level. A second integrator (106) is configured to generate a second voltage signal at a second integrator output indicative of an integral of the photodetector current level. A differential amplifier (108) receives the first voltage signal and the second voltage signal and generates a third output signal at a differential amplifier output indicative of a difference between the first voltage signal and the second voltage signal. The differential amplifier outputs the third voltage signal to an analog-to-digital conversion function input.