Note: Direct sensor resistance-to-frequency conversion with generalized impedance converter
Diego Ramı́rez Muñoz, J. Sánchez Moreno, Silvia Casans Berga, A. Edith Navarro Antón · Review of Scientific Instruments · 2010
In this note a squared output signal is generated from an astable circuit. Its frequency has a linear dependence on the resistance value of a resistive temperature sensor. The main circuit to obtain this direct relationship is the generalized impedance converter configured as a capacitor controlled by a sensor resistance. The proposed measurement method allows a direct analog-to-digital interface of information involved in resistive sensors. The converter finds applications in portable low voltage and low power design of instrumentation electronic systems.