Browsing by Author "Wang, Tong-Wen"

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An 80% Effeciency and Highly Adaptable PV Energy Harvest Circuitry With MPPT for IOT Devices
(2017-01-01)
Cheng, Yuan-Po
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Chao, Paul C. -P.
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Men, Guan-Yu
;
Yang, Ching-Cheng
;
Wang, Tong-Wen
An on-chip DC-DC converter for energy harvesting is proposed for a new battery-less solar cell tag applied to the Internet of Things (IoTs) devices. The main purpose of this design is to maximize the transfer efficiency and to stably provide a high enough supply voltage to the back-end loads. The overall circuit consists of a cross-coupled charge pump, a maximum power point tracking (MPPT) circuit, a timing control circuit and regulator. The input voltage range is from 0.45V to 3V. The output voltage can be boosted to the required level, in the range of 1V to 3.3V, with more than 60% power conversion efficiency. The throughput power is at least 500 mu W. A gated clock frequency modulation circuit is designed and adopted in the MPPT unit to lock the input resistance of the charge pump. In addition, a low-dropout (LDO) regulator circuit is used to provide a stable voltage to the load. The experimental results of chip show that the maximum power conversion efficiency (PCE) is 80% at 33 mu W input power condition.
Design and implement the readout circuit of an in-cell high-resolution capacitive touch panel
(2017-01-01)
Ku, Tsung-Yen
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Chao, Paul C. -P.
;
Huang, Chin-Hai
;
Liu, En-Chih
;
Yeh, Ming-Hua
This paper proposes a high resolution capacitive touch panel readout circuit to sense the Variation by self-capacitance method. This AM display of in-cell structure includes an active architecture for improved resolution, that controlling the TFT (Thin-film transistor) to make the accuracy better. In addition, the panel has 60 sensing point per 0.88 inches and the proposed readout circuit used switched capacitor charge amplifier(SCCA) to sensing the charge change and enhances the SNR (Signal-to-noise) by eliminating the baseline. The experimental results show that the proposed readout circuit SNR achieves 38dB and the frame rate is 200Hz.