ELECTRONIC MEASUREMENT CIRCUIT

摘要

The present invention concerns an electronic measurement circuit for measuring a physical parameter. The circuit comprises: a measurement sensor comprising two differential mounted capacitors each comprising a fixed electrode, and a common electrode, common to the two capacitors which is arranged to be movable relative to each fixed electrode of the two capacitors in order to alter the capacitive value of each capacitor when the physical parameter is measured. The circuit further comprises a first integrator unit connected to the common electrode for integrating charge received from the measurement sensor, and comprising two integrators arranged to be connected alternately to the common electrode; a second integrator unit connected to the first integrator unit for integrating charge received from the first integrator unit; a comparator for comparing analogue output values from the second integrator unit; a switch circuit connected to the measurement sensor for switching different voltage values across the two capacitors; and a feedback circuit for feeding a digital output signal of the comparator to the switch circuit for controlling the operation of the switch circuit.

主权项

1. An electronic measurement circuit for measuring a physical parameter, the circuit comprising:
a measurement sensor comprising two differential mounted capacitors each comprising a fixed electrode, and a common electrode, common to the two capacitors which is arranged to be movable relative to each fixed electrode of the two capacitors in order to alter the capacitive value of each capacitor when the physical parameter is measured; a first integrator unit connected to the common electrode for integrating charge received from the measurement sensor, and comprising two integrators arranged to be connected alternately to the common electrode via two switches; at least one intermediate integrator unit connected to integrate charge received from the first integrator unit, the or each intermediate integrator unit comprising two integrators arranged to integrate charge alternately from the two integrators of the first integrator unit; a comparator for comparing analogue output values from the two integrators of the or a last one of the at least one intermediate integrator unit; a switch circuit connected to the measurement sensor for switching different voltage values across the two capacitors; and a feedback circuit for feeding a digital output signal of the comparator to the switch circuit for controlling the operation of the switch circuit.