A temperature difference-to-frequency converter using resistance temperature detectors
Open Access
- 1 January 1990
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Instrumentation and Measurement
- Vol. 39 (4) , 676-677
- https://doi.org/10.1109/19.57259
Abstract
A novel temperature difference-to-frequency (TD/F) converter using two platinum resistance temperature detectors (RTDs) has been developed. The resistance difference of two RTDs is converted into a DC current to control the simulated inductor, which is designed so that its inductance is inversely proportional to the square of the current. The simulated inductor forms the resonant circuit of a Colpitts oscillator and hence the oscillation frequency becomes directly proportional to the resistance difference. A conversion sensitivity of 16 Hz/ degrees C and a residual nonlinearity of less than 2% over the temperature difference range of 35 degrees C to 155 degrees C are obtained by the prototype converter which oscillates at 667 Hz at a 51 degrees C temperature difference. The minimum detectable temperature difference is estimated to be +or-0.013 degrees C. The power dissipations in the RTDs are about 2 mu W. The proposed converter, except for the RTDs, can be fabricated in a monolithic IC form by scaling the component values.Keywords
This publication has 4 references indexed in Scilit:
- Highly accurate resistance deviation to frequency converter with programmable sensitivity and resolutionIEEE Transactions on Instrumentation and Measurement, 1986
- A Linear Temperature-to-Frequency Converter Using an Integrable Colpitts OscillatorIEEE Transactions on Instrumentation and Measurement, 1985
- Active- RC -circuit synthesis for the simulation of a grounded inductorElectronics Letters, 1984
- Lossless inductor simulation: novel configurations using d.v.c.c.s.Electronics Letters, 1980