Analog-to-digital conversion device, method and touch device

Abstract

The invention relates to an analog-to-digital conversion device, an analog-to-digital conversion method and a touch device, which is suitable for converting a partial voltage, wherein the partial voltage is generated according to a power voltage and a ground voltage. The analog-to-digital conversion device comprises a first sampling and hold circuit, a second sampling and hold circuit and an analog-to-digital converter, wherein the first sampling and hold circuit is used for sampling the partial voltage and holding the sampled partial voltage; the second sampling and hold circuit is used for sampling the power voltage and holding the sampled power voltage; the analog-to-digital converter is used for converting the held partial voltage to a digital value according to the held power voltage and the ground voltage; and the first sampling and hold circuit and the second sampling and hold circuit sample before the conversion of the analog-to-digital converter and hold during the conversion of the analog-to-digital converter.

Description

technical field [0001] The present invention relates to an analog-to-digital conversion device, a method, and a touch-sensitive device, in particular to an analog-to-digital conversion device, a method, and a touch-sensitive device that are not affected by voltage source disturbances. Background technique [0002] refer to figure 1 , a touch panel (Touch Panel) 11 includes a plurality of resistors (not shown) distributed in a mesh shape, and its two sides perpendicular to a first direction X are respectively applied with a panel power supply voltage TPVDD and a panel ground voltage TPGND , and the two sides perpendicular to a second direction Y are respectively applied with the panel power voltage TPVDD and the panel ground voltage TPGND. When the touch panel 11 is pressed, according to the principle of resistive voltage division, along the first direction X and the second direction Y, a voltage between the panel power supply voltage TPVDD and the panel ground voltage TPGND...

AI Technical Summary

Problems solved by technology

[0007] However, when the handheld mobile communication device transmits and receives signals, it will also cause interference to the panel power supply voltage TPVDD, causing the panel power supply voltage TPVDD to fluctuate

The voltage division generated by the touch panel 11 has a linear response to the fluctuation of the panel power supply voltage TPVDD, when the sample and hold circuit 13 is not used (such as figure 2 shown), the ratio of the input voltage of the successive approximation analog-to-digital converter 12 to the panel power supply voltage TPVDD is not affected by the fluctuation of the panel power supply voltage TPVDD, and the correct digital value can be converted, but when the sampling Hold circuit 13 when (as image 3 shown), the ratio of the input voltage of the successive approximation analog-to-digital converter 12 to the panel power supply voltage TPVDD will be affected by the fluctuation of the panel power supply voltage TPVDD, which will cause errors in the converted digital value

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