Tai-Cheng Lee

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—A discrete-time analog echo canceller is described that reduces the echo in the front end of Gigabit Ethernet twisted-pair interfaces. Echo cancellation in the analog domain by means of four taps reduces the complexity of the digital echo canceller and crosstalk cancellers. Designed in a 0.4-m CMOS technology, the circuit employs an LMS algorithm to adapt(More)
—A dual-operation-mode ring oscillator that employs dual-delay paths is presented. The two operation modes, referred to as the differential and common modes, have different output waveform characteristics and oscillation frequencies. A nonlinear model for the dual-delay-path ring oscillator and the analysis of the stability of each operation mode are(More)
—A discrete-time mixed-signal Gaussian frequency shift keying demodulator designed for a low intermediate frequency Bluetooth receiver performs FSK demodulation. Employing passive sampling and time-domain differentiation techniques, the demodulator performs quadrature demodulation while tolerating up to 200-kHz frequency offset. A distributed array of(More)