Browsing by Author "Lin, Chia-Hsiang"

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A Li-Ion Battery Charger With Smooth Control Circuit and Built-In Resistance Compensator for Achieving Stable and Fast Charging
(2010-02-01)
Lin, Chia-Hsiang
;
Hsieh, Chun-Yu
;
Chen, Ke-Horng
;
電控工程研究所
;
Institute of Electrical and Control Engineering
A built-in resistance compensator (BRC) technique is presented to speed up the charging time of a lithium-ion battery. A smooth control circuit (SCC) is proposed to ensure the stable transition from the constant-current (CC) to the constant-voltage (CV) stage. Due to the external parasitic resistance of the Li-ion battery-pack system, the charger circuit switches from the CC to the CV stage without fully charging the cell. The BRC technique dynamically estimates the external resistance to extend the CC stage. The experimental results show that the period of the CC stage can be extended to 40% of that of the original design. The charging time is effectively reduced.
A programmable dual hysteretic window comparator
(2008)
Huang, Hong-Wei
;
Lin, Chia-Hsiang
;
Chen, Ke-Horng
;
電控工程研究所
;
Institute of Electrical and Control Engineering
A programmable dual hysteretic window comparator is presented in this paper. The comparator uses a cascoded flipped voltage follower (CASFVF), a high speed V-I converter, and a current comparator to enhance the response time and accuracy. Moreover, the positive and negative hysteretic thresholds can be programmable, respectively. Simulation results in 0.25-mu m CMOS technology demonstrate the validity of the designed approach.
Built-in Resistance Compensation (BRC) Technique for Fast Charging Li-Ion Battery Charger
(2008)
Lin, Chia-Hsiang
;
Huang, Hong-Wei
;
Chen, Ke-Horng
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This paper presents a BRC technique to speed up the charging time of the Li-Ion battery. Based on the physical properties of the battery cell, the charger circuit charges the cell with three stages, which are trickle current (TC), constant current (CC), and constant voltage (CV) stages. Due to the internal parasitic resistance of the Li-Ion battery pack system, the charger circuit switches from the CC stage to the CV stage without fully charging the cell to the rated voltage value. At the CV stage, the cell is needed to be charged by a degrading current. The longer the cell stays at the CV stage, the longer the charging time is due to the degrading current. The BRC technique can dynamically estimate the internal resistance of the battery pack system to extend the period of the CC stage. The test chip was fabricated in TSMC 0.35-mu m process. Experimental results show the period of the CC stage can extended to about 40% that of the original design. The charging time can be effectively reduced.
Fast Transient Technique (FTT) in Buck Current-Mode DC-DC Converters for Low-Voltage SoC Systems
(2008)
Lin, Chia-Hsiang
;
Huang, Hong-Wei
;
Chen, Ke-Horng
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This paper proposes a fast transient technique (FTT) to achieve excellent transient response of current-mode buck DC-DC converters. The proposed technique combines a non-linear control and a linear control mechanism to achieve fast transient response time, low output ripples, and stable transient operation at the same time. The test chip was fabricated in UMC 0.18-mu m process. Experimental results show that the transient undershoot/overshoot voltage and the recovery time are not exceed 48mV and 10 mu s, respectively.
High-Performance Low-Dropout Regulator Achieved by Fast Transient Mechanism
(2008)
Huang, Hong-Wei
;
Lin, Chia-Hsiang
;
Chen, Ke-Horng
;
電控工程研究所
;
Institute of Electrical and Control Engineering
An adaptive reference control (ARC) technique is proposed for minimizing overshoot/undershoot voltage and settling time of low-dropout regulators (LDO). Linear operation provided by ARC technique can dynamically and smoothly adjust the reference voltage for increasing slew rate of error amplifier and forcing output voltage back to its steady-state value rapidly. The amount of transient revision is proportional to transient-state output voltage variation and load condition. In addition, dynamic push-pull technique is used to enhance transient response. Experimental results demonstrate the undershoot voltage, settling time and load regulation are improved 31%, 68.5% and 70% when load current changes between 1 mA and 100 mA.
Low-Dropout Regulators With Adaptive Reference Control and Dynamic Push-Pull Techniques for Enhancing Transient Performance
(2009-03-01)
Lin, Chia-Hsiang
;
Chen, Ke-Horng
;
Huang, Hong-Wei
;
電控工程研究所
;
Institute of Electrical and Control Engineering
An adaptive reference control (ARC) technique is proposed for minimizing overshoot/undershoot voltage and settling time of low-dropout regulators. Linear operation provided by the ARC technique can dynamically and smoothly adjust the reference voltage so as to increase the slew rate of error amplifier thus forcing the output voltage back to its steady-state value rapidly. The amount of transient revision is proportional to transient state output voltage variation and load condition. In addition, a dynamic push-pull technique is used to enhance transient response. Experimental results demonstrate that the undershoot voltage, settling time, and load regulation are improved by 31%, 68.5%, and 70%, respectively, when load current changes between 1 and 100 mA.