p-n Diode Parameter Extraction

One may propose that the actual implementation of a device as a transducer in a sensing application circuit provides strong validation of its extracted inherent parameters. This route is especially true when there are alternative sensors for the purpose of comparing the measurements. This chapter presents a novel application that relies on observations of p-n diode voltage under various constant currents. The measurements are compared with two alternative thermometers. The voltage across a p-n diode is repeatable in this connection. The following discussion demonstrates a novel approach for use in a direct measuring thermometer with a kelvin scale. Importantly, this approach simplifies the complexities often associated with p-n diode thermal sensors by reducing the need for conditioning circuits, eliminating the requirement for delicate voltage references, and removing the need for calibration. In our test application, a microcontroller modulates the current flowing through the diode, switching between two predefined values. The buffered diode voltage is channeled subsequently into the microcontroller’s analog-to-digital converter (ADC), enabling straightforward temperature readout on a compatible device with minimal programming requirements. Finally, we assess the prototype’s performance against two established standards, thereby providing validation for this innovative approach. The chapter concludes that by implementing a theoretically predicted mode, one can indirectly confirm the validity of the methods of extracting the inherent parameters of the diode.