A touch screen control system circuit detection

The present invention relates to a capacitive touch screen controller chip field, a new touch-screen control and measurement system circuit, use capacitor charging, charge sharing, charge subtraction and charge transfer in four parts, in which the charge-charge phase by the differential op amp and the op amp inverting input terminal connected to the capacitor and switch composition, charge sharing is detected by detecting the capacitance change of the external, electric charge; charge-subtraction is implemented offset cancellation charge; charge transfer charge is converted into voltage by the internal analog to digital the quantized converter. The invention uses a detection system can detect a change in capacitance scanning channel capacitance between the ground, the detection system is simple, wide application, take up less chip area, low cost, with better noise immunity.