This Letter presents a self‐capacitance sensing (SCS) technique for touch screen panel with the alternating panel charge sharing (APCS) that effectively suppresses low‐frequency noise and achieves a better signal‐to‐noise ratio (SNR). With the proposed APCS‐based SCS, SNR is improved in measurement by 7.65 dB compared to the conventional panel charge sharing‐based SCS.

This paper presents a fully-differential touch screen panel (TSP) self-capacitance sensing (SCS) system with a self-capacitance mismatch calibration technique. Due to the self-capacitance mismatch of TSP, the analog front-end (AFE) of the receiver (RX) circuit suffers from dynamic range degradation and gain limitations, which lead to the signal-to-noise ratio (SNR) loss for the TSP SCS system. The proposed calibration introduces the difference in input resistance and the driving amplifier’s strength between the fully-differential input. Thus, the mismatch effect is efficiently relieved in terms of area and power consumption. The proposed calibration restores the SNR by 19.54 dB even under the worst self-capacitance mismatch case.

This paper presents a Class-C voltage-controlled oscillator (VCO) with bias voltage calibration that automatically finds the low-phase noise point and achieves robust start-up regardless of PVT variation. This VCO structure also has the bias circuit that compensates for temperature changes even when calibration is not applied. Through these techniques, the problems of robust start-up and vulnerability to PVT variation, which are chronic problems of Class-C VCO, are overcome. The proposed VCO was designed in a 28 nm CMOS process. Simulation results show that this VCO has an operating range from 3.717 to 4.675 GHz, resulting in a frequency tuning range (FTR) of 22.8%. In addition, power consumption was 2.135 mW, phase noise at 1 MHz was −124.1 dBc/Hz, and the figure of merit (FoM) was −192.2 dBc/Hz. The chip area was very small at 0.196 mm2.