ScholarWorks@성균관대학교

초록

This brief presents an auto-correlated host sensing analog front-end (AFE) for active stylus systems, enabling host-stylus pairing without periodic display-disturbing beacon signals. The proposed AFE employs a dynamic-range-boosting differential dual-output current conveyor (DRB-DDCC) and an incremental current-mode continuous-time delta-sigma modulator (ICTDSM) in the data path to enhance signal-to-noise ratio (SNR) for weak charge signals under hovering conditions. An accompanying clock path integrates a limiting amplifier (LA) and a digital phase tracking loop (DPTL) to support auto-correlated demodulation. Fabricated in an 80-nm CMOS process, the prototype achieves host sensing in both touch and 10-mm hovering conditions, demonstrating SNRs of 47.8 dB and 33.8 dB, respectively, at a frame rate of 1 kHz. The fabricated AFE consumes 1.07 mW and occupies an active area of 0.137 mm2

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