Voltage shifting double integration circuit for high sensing resolution of large capacitive touch screen panels

We propose a new touch screen sensing circuit based on voltage shifting double integration scheme for large touch screen panels. The proposed circuit increases the sensing resolution by shifting integrated signal, while reducing the detection time by integrating both edges of sense signals. We implemented the proposed technique in FPGA and analog circuit with touch detection software. Experiments show that the proposed circuit improves both the touch performance and frame rate - key requirements for large touch screen controllers.