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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

关键词： RTD   温度传感器   振荡器电路