Touch key sensitivity adjusting method and circuit and touch switch

Abstract

The invention provides a touch key sensitivity adjusting method, a touch key sensitivity adjusting circuit and a touch switch. According to the touch key sensitivity adjusting method, a first end of afirst capacitor is connected with a zero level through a first CMOS switch; the first end of the first capacitor and the first end of a second capacitor are connected through a second CMOS switch; the first CMOS switch and the second COMS switch are set to be opposite in the period; the first end of the second capacitor is also connected to the output end of the adjustable current source and thefirst input end of the comparator; a comparison voltage VREF is connected to a second input end of the comparator; when the end voltage of the second capacitor is smaller than VREF, the adjustable current source outputs charging current to be adjusted to be I; when the voltage of the second capacitor end is larger than VREF, the charging current of the adjustable current source is adjusted to lambda * I, whether a key is pressed down or not is determined by judging the output of the comparator, and sensitivity adjustment is achieved by adjusting lambda. According to the touch key sensitivity adjusting method, the sensitivity of the touch switch can be flexibly adjusted by adjusting the proportion of the charging current.

Description

technical field [0001] The invention relates to the field of switch control, in particular to a touch button sensitivity adjustment method, a circuit and a touch switch. Background technique [0002] With the development of electrical and electronic technology, household electrical appliances are increasingly popular and electronic, radio and television, post and telecommunications and computer networks are increasingly developed, and the electromagnetic environment is becoming increasingly complex and deteriorating, making the electromagnetic compatibility (EMC, electromagnetic interference, EMI and The problem of electromagnetic anti-EMS has also been paid more and more attention by governments and production enterprises of various countries. Electromagnetic Compatibility (EMC) of electronic and electrical products is a very important quality index. It is not only related to the working reliability and safety of the product itself, but also may affect the normal work of ot...

AI Technical Summary

Problems solved by technology

In actual products, the touch button and the human body are usually separated by a panel. Due to the different panel materials and thicknesses of various manufacturers, it may cause the chip to fail to achieve uniform button sensitivity and anti-interference ability when implementing different solutions.

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