Digital to analog converter and multiplexer for capacitance detection

Abstract

The invention discloses a digital to analog converter and a multiplexer for capacitance detection. A capacitance path is connected in parallel in a voltage path. The capacitance path special for measuring the capacitance is added, and measurement of the capacitance can be finished through the capacitance path with the digital to analog converter in a chip, so that only a small quantity of electronic devices are added, and the area and cost of the chip can be saved effectively.

Description

technical field [0001] The invention belongs to the field of electronics, in particular to a touch button circuit. Background technique [0002] Touch button technology has gradually become popular in the field of consumer electronics represented by mobile phones and tablet computers in recent years. As a human-machine interface, touch buttons have the advantages of durability, beauty, and small size compared with mechanical buttons. [0003] There is already a special chip for capacitance detection on the market. This chip generally converts different capacitance values ​​into signals of different frequencies, and then judges whether the frequency of the signal changes too much by timing. If it does change a lot, it is judged as A touch event occurs. This chip is generally used in scenarios where the anti-interference requirements of the touchpad are not high and the control function is relatively simple. [0004] In most consumer electronics, there is usually a main con...

AI Technical Summary

Problems solved by technology

But in capacitance measurement, since the physical quantity measured is not voltage, this multiplexer and DAC architecture is not applicable

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