Capacitor voltage conversion device

Abstract

The invention provides a capacitor voltage conversion device, and the device comprises: a charge integration module which comprises a first operational amplifier, a feedback capacitor, and a third switch; a sample hold module which comprises a third capacitor, a fourth capacitor, a fifth capacitor, a second operational amplifier and a plurality of switches, wherein one end of the fifth capacitor is connected with the other end of the third capacitor, the other end of the fifth capacitor is connected with the output end and the in-phase input end of the second operational amplifier through twoswitches, the fourth capacitor is in bridge connection with the output end and the reverse input end of the second operational amplifier, and the in-phase input end of the second operational amplifieris also connected with a reference voltage input end; and at least one adjustable capacitance compensation module, wherein each adjustable capacitance compensation module comprises a plurality of capacitor branches connected in parallel, and each capacitor branch comprises a compensation capacitor and an adjusting switch; wherein one or more of a detection capacitor and a feedback capacitor of the detection sensor are adjustable capacitance compensation modules.

Description

technical field [0001] The present disclosure relates to the technical field of integrated circuits, in particular to a capacitive voltage conversion device. Background technique [0002] Capacitive sensors are widely used sensors, such as pressure sensors, accelerometers, gyroscopes, etc. In recent years, MEMS (Micro-Electro-Mechanical System) has developed very rapidly. With the popularization of MEMS technology, MEMS sensors have emerged as the times require. MEMS sensors have the advantages of small size, light weight, low price, and easy integration with CMOS readout circuitry. However, due to its small size, the capacitance value of the sensor is generally on the order of pF, and the output capacitance change is very weak, often only a few or tens of fF. If it is connected to an external circuit, parasitic capacitance, distribution parameters, etc. The useful signal has a great influence, and it is necessary to detect the change of the tiny capacitance through the de...

AI Technical Summary

Problems solved by technology

The switched capacitor detection structure circuit is relatively simple, but in practical applications, there are problems such as clock feedthrough, charge injection, switching noise, parasitic parameters, etc., which limit the accuracy of capacitance detection and conversion

Moreover, most of the current capacitive sensor detection circuits are specially designed for specific sensors, which cannot be applied to other sensors of the same type, and the design cost is high.

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