Applications of integrated solar cells in low noise instrumentation

Small sized solar cells in compact SOIC packages are investigated as candidates for the design of floating low noise voltage reference to be used in low noise applications. The noise introduced by the solar cell as a function of the incident light is investigated and a simplified model is extracted that can be used, together with a proper filtering stage and a closed loop control system, for the implementation of very low noise, high accuracy programmable voltage and current sources. In proper conditions and down to a few hundreds mHz, the residual low frequency noise of such sources can be reduced down to the noise introduced by the very low noise JFET devices employed for the realization of the output buffer (voltage sources) or of the voltage to current converter (current sources).