A highly area-efficient controller for capacitive touch screen panel systems

Tong-Hun Hwang, Wen-Hai Cui, Ik-Seok Yang, Oh-Kyong Kwon
2010 IEEE transactions on consumer electronics  
In this paper, a highly area-efficient controller for capacitive touch screen panels (TSPs) is proposed. The proposed controller uses a 10-bit successive approximation register analog-to-digital converter (SAR ADC) with an adder to compensate for the capacitance variation in the TSP and for the offset voltage variation in the charge amplifier of the sensing circuit. By using the proposed compensation method, the area of the controller can be reduced by 90.3% of the area of the conventional
more » ... ollers. The measurement results showed that the signal-to-noise ratio (SNR) of the controller increases from 12.5 to 21.3 dB after compensation. Also, its spatial jitter decreases from ±1.5 to ±0.46 mm, which is 7% of the sensor pitch of 8 mm. 1
doi:10.1109/tce.2010.5506047 fatcat:qujzt5id25fsjiulajtjyptbse