Browsing by Author "Liu, Ming-Cheng"

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A low-power reference-less clock/data recovery for visible light communication devices requiring low data throughput
(2020-01-01)
Liu, Ming-Cheng
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Pribadi, Eka Fitrah
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Chao, Paul C-P
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Pandey, Rajeev Kumar
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電子工程學系及電子研究所
In this study a reference-less clock and data recovery (CDR) is designed and developed for the low speed visible light communication system based Internet of Things (IoT) tags. Design system incorporates an off-chip photodiode and an integrated-on chip front-end receiver with the reference-less CDR. For an IoT tags low power consumption, low supply voltage, and small area are the major design constraint. Considering these constraints, the circuit of the front-end receiver incorporate the near-threshold cascode current mirror based transimpedance amplifier, low pass filter and a comparator. On the other-hand, low power all-digital phase locked loop-based reference-less CDR is design herein with a modified loop filter, auto tune digital control oscillator and auto duty cycle adjustment circuit. The circuit is implemented in an integrated chip with area of 0.728 mm(2) via TSMC 180 nm process. Experimental measurement results of the tapeout chip shows that the phase noises are - 39.54 dBc/Hz @ 1 kHz, - 80.35 dBc/Hz @ 10 kHz and - 92.26 dBc/Hz @ 100 kHz. The measured jitter in the recovered clock is 3.312 ns (0.0033 UI). At 1 Mbps, the measured total power consumption is 5.58 mu W. The achieve results shows that the implemented circuit in this study highly support the commercial low data rate based optical wireless sensing nodes for IoT tags.
Low-power and Reference-Less data and clock recovery circuit for visible light receivers
(2018-01-01)
Liu, Ming-Cheng
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Chao, Paul C. -P.
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Khiong, Soh Sze
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
In this paper a low power all-digital clock and data recovery (ADCDR) with 1Mhz frequency has been proposed. The proposed circuit is designed for optical receiver circuit on the battery-less photovoltaic IoT (Internet of Things) tags. The conventional RF receiver has been replaced by the visible light optical receiver for battery-less loT tags. With this proposed ADCDR a low voltage, low power consumption & tiny IoT tags can be fabricated. The proposed circuit achieve the maximum bandwidth of 1 MHz, which is compatible with the commercial available LED and light sensor. The proposed circuit has been fabricated in TSMC 0.18um 1P6M standard CMOS process. Experimental results show that the power consumption of the optical receiver is approximately 5.58uW with a supply voltage of 1V and the data rate achieves 1Mbit/s. The lock time of the ADCDR is 0.893ms with 3.31ns RMS jitter period.