| 摘要 |
The electronic measurement circuit comprises a measurement sensor (1) with two differential mounted capacitors (C1, C2) each comprising a fixed electrode, and a common electrode arranged to move relative to the fixed capacitor electrode to alter the capacitive value when the physical parameter is measured. The circuit further comprises a first integrator unit (5) connected to the common electrode for integrating charge received from the sensor, and comprising two integrators arranged to be connected alternately to the common electrode, a first comparator (9) for comparing analogue output values from the first integrator unit, a second integrator unit (7) for integrating charge received from the first integrator unit (5), a second comparator (19) for comparing analogue output values from the second integrator unit, a switch circuit (3) for switching different voltage values across the capacitors, and a feedback circuit (11) for feeding a digital output signal (ai) from the first comparator to the switch circuit for controlling its operation, and an incremental calculation unit (13) receiving digital output signals (ai, bi) from the comparators and supplying a final digital output signal (y). |
