Patent ID: 9542900
Date: 2017-01-10
CPC Classifications: G06F,G09G

Claim:
1. A circuit for detecting a touch point location on a touch panel, comprising: a sensing sub-circuit, an amplification sub-circuit connected to the sensing sub-circuit, an output sub-circuit connected to the amplification sub-circuit, a detection sub-circuit connected to the output sub-circuit, and a first touch drive electrode line, wherein the sensing sub-circuit comprises a fixed capacitor, a variable capacitor, and a first switch transistor; and wherein a gate terminal and a source terminal of the first switch transistor are connected to the first touch drive electrode line, a drain terminal of the first switch transistor is connected to a terminal of the fixed capacitor, a terminal of the variable capacitor is connected to the other terminal of the fixed capacitor, the other terminal of the variable capacitor is connected to a reference voltage, and the amplification sub-circuit is connected to the terminal of the fixed capacitor that is connected to the variable capacitor, wherein the amplification sub-circuit comprises a second switch transistor, a third switch transistor, and a amplification transistor, a gate terminal of the second switch transistor being connected to the terminal of the fixed capacitor that is connected to the first switch transistor, a gate terminal of the third switch transistor being connected to the terminal of the fixed capacitor that is connected to the variable capacitor, a drain terminal of the second switch transistor being connected to a source terminal of the third switch transistor, a source terminal of the second switch transistor being connected to a high level voltage source, a drain terminal of the third switch transistor being connected to a low level voltage source, a gate terminal of the amplification transistor being connected to the drain terminal of the second switch terminal, a drain terminal of the amplification transistor being connected to the output sub-circuit, and a source terminal of the amplification transistor being connected to the high level voltage source.