Browsing by Author "Lee, Hui-Hsuan"

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A 2 GOPS Quad-Mean Shift Processor with Early Termination for Machine Learning Applications
(2014-01-01)
Tsai, Chang-Hung
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Lee, Hui-Hsuan
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Yu, Wan-Ju
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Lee, Chen-Yi
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電機工程學系
This paper proposes a 2 GOPS quad-mean shift processor (Q-MSP) architecture for data clustering and machine learning applications. By exploiting the linear approximation approach and early termination mechanism, the proposed algorithm can reduce 70% and 40% computational complexity, respectively. Moreover, 4 mean shift processor cores are integrated into the proposed architecture to support parallel processing to further improve system performance. Implemented in Xilinx Virtex-7 FPGA, this architecture occupies 65k LUTs and 3.3MB block memory to achieve 2 GOPS throughput operated at 125MHz.
A Single-Inductor Dual-Input Dual-Output (SIDIDO) Power Management with Sequential Pulse-Skip Modulation for Battery/PV Hybrid Systems
(2016-01-01)
Lee, Hui-Hsuan
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Chen, Po-Hung
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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 single-inductor dual-input dual output (SIDIDO) power converter with sequential pulse-skip modulation (SPSM) is proposed for IoT applications. It manages power from a 1.4-V zinc-air battery and a 0.55-V to 0.7-V photovoltaic (PV) module to prolong the battery life. The proposed converter employs buck-boost mode and buck mode for PV module and the battery, respectively, to produce two different output voltages. The input sources are automatically selected by mode detection circuit which monitors both PV voltage and the output voltage to minimize the battery usage. The proposed SPSM along with a constant voltage maximum power point tracking (MPPT) method controls output voltages with low cross regulation while extracting the maximum power from a PV module. The measurement results demonstrate a peak efficiency of 89 % with an available input voltage of 0.55 V to 1.4 V.
A Single-Inductor Triple-Input-Triple-Output (SITITO) Energy Harvesting Interface with Cycle-by-Cycle Source Tracking and Adaptive Peak-Inductor-Current Control
(2017-01-01)
Liu, Chi-Wei
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Chung, Ming-Jie
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Lee, Hui-Hsuan
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Liao, Pei-Chun
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Chen, Po-Hung
In this paper, a single-inductor triple-input-triple-output (SITITO) buck-boost converter with cycle-by-cycle source tracking (CCST) is developed for multi-source energy harvesting. The proposed CCST is capable of harvesting power from the PV and TEG simultaneously, and automatically selects the appropriate source according to the maximum power point (MPP) of the transducers in each switching cycle. The converter provides two regulated outputs for the analog (V-OUT1 = 1.2 V) and the digital (V-OUT2 = 0.4-0.6 V) circuits, while storing the excess energy in a storage capacitor (C-OUT3). An adaptive on-time (AOT) circuit with an adaptive peak-inductor-current (APIC) control is developed for dynamically adjusting the on-time based on the input voltage (V-IN) to obtain high conversion efficiency under different V-IN. The proposed converter achieves a peak efficiency of 84.4% with an available input voltage of 0.05 V to 0.8 V. Compared to the conventional constant peak-inductor-current (CPIC) control, the proposed APIC improves 11 % efficiency at low V-IN.
Digital Buck Converter With Switching Loss Reduction Scheme for Light Load Efficiency Enhancement
(2017-02)
Wu, Chung-Shiang
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Lee, Hui-Hsuan
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Chen, Po-Hung
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Hwang, Wei
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電子工程學系及電子研究所
In this brief, we present a digital pulsewidth modulation buck converter with a switching loss reduction scheme to improve conversion efficiency at light load conditions. The proposed switching loss reduction scheme combines power-stage voltage swing scaling, transistor width scaling, and controller voltage scaling to reduce the dynamic power dissipation of the system. The power-stage voltage swing scaling also reduces the inductor current ripple at light load conditions, which extends the available output current range in the continuous conduction mode (CCM). A duty ratio estimation mechanism is implemented to provide a modulated signal with the correct duty ratio to control the output voltage. Experimental results demonstrate a 38% conversion efficiency improvement at a 50-mu A output current. In addition, the proposed circuit achieves a 96% peak efficiency with an output current ranging from 20 mu A to 30 mA in the CCM operation.
Dual-Source Energy-Harvesting Interface With Cycle-by-Cycle Source Tracking and Adaptive Peak-Inductor-Current Control
(2018-10-01)
Liu, Chi-Wei
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Lee, Hui-Hsuan
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Liao, Pei-Chun
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Chen, Yi-Lun
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Chung, Ming-Jie
In this paper, we present a single-inductor triple-input-triple-output (SITITO) buck-boost converter in a 0.18-mu m CMOS process for dual-source energy harvesting. The converter operates in the single-source mode, dual-source mode (DSM), and backup mode automatically by detecting the input and output conditions. Converter operation in the proposed DSM enables extraction of power from both a photovoltaic cell and a thermoelectric generator in one switching cycle for efficient power extraction. The cycle-by-cycle source-tracking approach selects the appropriate input source according to the maximum power point of the energy transducers. The adaptive on-time circuit with the proposed adaptive peak-inductor-current (APIC) control adjusts the on-time of power transistors to obtain high conversion efficiency under different input voltages. The experimental results demonstrate that the proposed SITITO converter has a peak efficiency of 84.4%. When compared with the conventional constant peak-inductor-current control, an efficiency improvement of 11% is obtained via the proposed APIC control.
Single-Inductor Dual-Input Dual-Output Battery-PV Hybrid System With 2-D Adaptive On-Time Control for Internet of Things
(2020-03-01)
Lee, Hui-Hsuan
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Liu, Chi-Wei
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Takamiya, Makoto
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Chen, Po-Hung
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電子工程學系及電子研究所
In this article, we present a single-inductor dual-input dual-output power converter with two-dimensional adaptive-on-time (2-D AOT) control for Internet of things (IoT) applications. The proposed system combines energy from a 0.55-0.7 V photovoltaic (PV) module with a non-rechargeable 1.4-V zinc-air battery to extend the battery life. The proposed converter employs the buck-boost mode and the buck mode for the PV module and the battery, respectively, to produce two output voltages for different loading currents. The proposed 2-D AOT technique not only reduces the output voltage ripple but also improves the dual-source conversion efficiency over a wide input voltage range. Moreover, the response time of the self-tracking zero-current detector can also be improved by the proposed 2-D AOT. We fabricated the test chip using 0.18-mu m technology in an area of 1.9 x 2.2 mm(2). The measurement results demonstrated a peak efficiency of 92.5% with an input voltage range of 0.55-1.4 V. The output voltage ripple was less than 2.3% VOUT under different input voltage ranges.