Temperature Compensation in Optical Sensing System

A temperature compensation circuit for a light source (e.g., light emitting diode (LED)) whose radiant energy output decreases when ambient temperature increases includes a first circuit element for generating a first current that increases proportional to an increase in the ambient temperature, and a second circuit element for generating a second current that is first order independent of the ambient temperature. The circuit further includes a weighted current adder for generating a third current by combining the first and second currents with first and second weights applied to the first andsecond currents respectively. The circuit further includes a third circuit element responsive to the third current for supplying a fourth current to the light source to maintain a radiant energy output of the light source constant independent of the ambient temperature. 公开了种用于光源(例如发光二极管(LED))的温度补偿电路，所述光源的辐射能量输出在环境温度升高时减小。所述电路包括用于提供与环境温度的升高成比例地增加的第电流的第装置以及用于提供与环境温度阶无关的第二电流的第二装置。所述电流还包括加权电流加法器，所述加权电流加法器用于通过以分别施加到第电流和第二电流的第