This application note shows how to design a temperature sensor oscillator circuit using Microchip’s low-cost MCP6001 operational amplifier (op amp) and the MCP6541 comparator. Oscillator circuits can be used to provide an accurate temperature measurement with a Resistive Temperature Detector (RTD) sensor. Oscillators provide a frequency output that is propor- tional to temperature and are easily integrated into a microcontroller system. RC oscillators offer several advantages in precision sensing applications. Oscillators do not require an Analog-to-Digital Converter (ADC). The accuracy of the frequency measurement is directly related to the quality of the microcontroller’s clock signal and high-frequency oscillators are available with accuracies of better than 10 ppm. AN895 Oscillator Circuits For RTD Temperature Sensors Author: Ezana Haile and Jim Lepkowski RTDs serve as the standard for precision temperature Microchip Technology Inc. measurements because of their excellent repeatability and stability characteristics. A RTD can be character- ized over it’s temperature measurement range to INTRODUCTION obtain a table of coefficients that can be added to the ……