Hyongmin Lee

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In this paper, we describe a cyclic ADC to adopt the comparator-based switched-capacitor (CBSC) technique, for the first time, so as to compensate for the technology scaling and reduce power consumption by eliminating the need for high gain opamps. A boosted preset voltage is also introduced to improve the conversion rate without consuming more power. The(More)
We present a sensor readout integrated circuit for the CNT bio-sensor array, the heart of which is our low-power current-input continuous-time ΔΣ modulator that is capable of dynamic range extension. Experimental results show that the prototype chip, designed and fabricated in 0.18μm CMOS process, achieves a dynamic range of 87.746dB and has(More)
We propose a low-voltage low-power clock and data recovery (CDR) circuit which incorporates a relaxation-based voltage-controlled oscillator and clock-edge modulation, which eliminates the need for an external reference clock without allowing harmonic locking. This CDR supports input data rates between 200 kbps and 10 Mbps at 0.7 V and operates up to 24 MHz(More)
In this paper, we have proposed a new approach for optical failure analysis which employs a CMOS photon-emitting circuitry, consisting of a flipflop based on a sense amplifier and a photon-emitting device. This method can be used even with deepsubmicron processes where conventional optical failure analyses are difficult to use due to the low sensitivity in(More)
This brief proposes an amplitude shift keying (ASK) demodulator that uses switched-capacitor differentiators to make it compliant with the very high bit rate amendment to the ISO/IEC 14443 standard for contactless smart card applications. These differentiators detect transitions in modulated ASK signals with a carrier frequency of 13.56 MHz at data rates up(More)
This paper proposes a low-power referenceless clock and data recovery (CDR) circuit for biomedical devices or sensor applications. Its power consumption is reduced by adopting clock-edge modulation technique and using a voltage-controlled oscillator (VCO) based on a relaxation oscillator. Clock-edge modulation eliminates the need for an external reference(More)
A flexible clinical ultrasound system must operate with different transducers, which have characteristic impulse responses and widely varying impedances. The impulse response determines the shape of the high-voltage pulse that is transmitted and the specifications of the front-end electronics that receive the echo; the impedance determines the specification(More)
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