Capacitance digital conversion circuit

Abstract

The invention discloses a capacitance digital conversion circuit, a capacitance digital conversion method and an electronic chip. The capacitance digital conversion circuit comprises a first module, a comparator and a dynamic range adaptive sliding module, wherein the first module comprises a successive approximation unit, a first adder, a first digital-to-analog converter, a second adder, a third adder and an integral unit which are connected in sequence, and further comprises a second digital-to-analog converter connected with the third adder; the comparator, the dynamic range adaptive sliding module and the first adder are connected in sequence; and the comparator is connected with the second digital-to-analog converter. According to the capacitance digital conversion circuit provided by the invention, adverse effects on DSM fine quantization caused by errors of parasitism, interference and the like on an SAR quantization result can be avoided, so that the adverse effects caused by parasitism and interference are well avoided, the capacitance digital conversion circuit can work in a more severe environment, the robustness of the circuit is obviously improved, and the application range of the circuit is expanded.

Description

technical field [0001] The present application relates to the technical field of integrated circuits, in particular to a capacitance-to-digital conversion circuit. Background technique [0002] With the development of IoT chip technology, more and more sensor chips are being deployed on the node side of the IoT. Wider deployment needs to consider cost and power consumption. On the one hand, it is hoped that the chip cost is low enough when deploying. On the other hand, In the later maintenance, it is hoped that the power supply will be supplied once, and it will be "permanently used". The battery does not need to be replaced midway. It is also hoped that the sensor chip can still work normally in harsh environments. Capacitive sensing chips, as a low-cost, high-energy-efficiency sensing interface circuit, have broad application prospects in the sensing end of the Internet of Things. Based on capacitive sensing chips, humidity sensing, pressure sensing, acceleration sensing,...

AI Technical Summary

Problems solved by technology

Capacitive sensing based on SAR has high energy efficiency, but the resolution is low, which limits the application at the sensing end; capacitive sensing based on DSM has high precision, but the power consumption of the integrator is too high, and the energy efficiency is limited. In addition, it is limited by the output swing of the amplifier, and the input dynamic range is relatively small; the capacitive sensing based on Zoom can better balance the accuracy and dynamic range, but in order to coordinate the work of the front and rear stages, it is necessary to leave a space between the electrodes. Redundancy, but too large redundancy will lead to the loss of precision, resulting in a decrease in energy efficiency, and too small redundancy will reduce the robustness of the chip. Therefore, it is urgent to develop an A technical solution that can guarantee high robustness

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