TOUCH SIGNAL GAIN CONTROL APPARATUS AND METHOD

摘要

A touch signal gain control apparatus includes an analog gain stage, a digital gain stage, a gain control module, and a comparing module. The analog gain stage and digital gain stage are coupled to the input terminal and output terminal of an analog-digital converter. When the comparing module generates a comparing result according to a voltage signal inputted to analog gain stage, the gain control module controls analog gain stage to amplify voltage signal in an analog magnification according to comparing result to form an amplified voltage signal not over an input threshold. The analog-digital converter converts amplified voltage signal into a digital signal. The gain control module controls digital gain stage to amplify digital signal in a digital magnification according to comparing result to form an amplified digital signal. The product of analog magnification and digital magnification equals to ratio of amplified digital signal and voltage signal.

主权项

1. A touch signal gain control apparatus, applied in a touch sensing apparatus comprising an analog-digital converter and coupled to an input terminal and an output terminal of the analog-digital converter respectively, the touch signal gain control apparatus comprising:
an analog gain stage, coupled to the input terminal of the analog-digital converter; a digital gain stage, coupled to the output terminal of the analog-digital converter; a gain control module, coupled to the analog gain stage and the digital gain stage respectively; and a comparing module, coupled between the input terminal of the analog-digital converter and the gain control module; wherein when the comparing module generates a comparing result according to a voltage signal inputted to the analog gain stage and an input threshold of the analog-digital converter, the gain control module controls the analog gain stage to amplify the voltage signal in an analog magnification according to the comparing result to form an amplified voltage signal not over the input threshold, and then the analog-digital converter converts the amplified voltage signal into a digital signal, the gain control module controls the digital gain stage to amplify the digital signal in a digital magnification according to the comparing result to form an amplified digital signal, wherein the product of the analog magnification and the digital magnification equals to a gain ratio of the amplified digital signal and the voltage signal.