Adiabatically driven touch controller analog front-end for ultra-thin displays

Thinner displays are continuously developing for reducing form factor of mobile devices. To manufacture the display be thin, touch screen panel layers are directly patterned on top of the display active layers generating huge capacitive coupling between them. Therefore, the touch screen controller (TSC) have to stimulate over heavily coupled touch sensing channels and endure heavily affected noise from the display operation. To overcome adverse effects of recent incorporated touch-display panel development, this paper presents an analog front-end (AFE) of a TSC with the adiabatic charge recycling driver to effectively generate stimuli. The AFE adopts correlated-noise-sampling-embedded modulation on top of fully differential filtering stages overcoming adverse effects of continually developing ultra-thin mobile displays. Fabricated in a 0.18μm CMOS process, the adiabatically driven AFE provides a signal-to-noise-ratio (SNR) of 51.5dB with a 4mmφ touch at 120Hz frame rate and achieves a 14.7dB SNR improvement via noise sampling. The AFE consumes 23.7mW and occupies an active area of 9.1mm
²
.