Browsing by Author "Lin, Yung-Hsin"

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Power MOSFET array in LDO regulator compensation
(2007)
Lin, Yung-Hsin
;
Zheng, Kuo-Lin
;
Chen, Ke-Horng
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This paper proposes an equivalent power MOSFET array for implementing smooth pole tracking in Low-dropout (LDO) regulator compensation. As we know, turning on/off the power transistors in proper sequence alleviates the ground bounce effects. Thus, power MOSFET array with suitable turn-on/off sequence is presented to suppress the output ripples in case of load variations. Besides, load dependent power MOSFET array also provides a smooth pole tracking in order to effectively compensate LDO regulator. Experimental results demonstrate good performance of fast and smooth pole tracking. Compared to conventional pole tracking technique, the new technique has low output ripples and fast response time. This technique is a good solution for RF SoC applications.
Smooth Pole Tracking Technique by Power MOSFET Array in Low-Dropout Regulators
(2008-09-01)
Lin, Yung-Hsin
;
Zheng, Kuo-Lin
;
Chen, Ke-Horng
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This paper proposes an advanced Q-reduction technique of pole-splitting compensations for low dropout (LDO) regulator. The output pole is load dependent and may cause the scenario of complex poles when load current changes. LDO regulators may oscillate because high-Q incurs the less gain and phase margins. The reasons of causing complex poles depend on the design methodology. For the design of capacitor-free LDO regulator, high-Q issue happens when load current changes from heavy to light. Recent literature provides a method to alleviate the high-Q problem. However, large dropout voltage in case of suddenly large loads forces designers to include a small load capacitor as an indispensable component for supplying system-on-chip (SoC) systems. Different to the case of capacitor-free LDO regulators, high-Q issue happens when load current changes from light to heavy. According to our proposed power MOSFET array, the high-Q problem can be alleviated and prevent LDO regulators from oscillating when load changes. Experimental results promise the stability and show the improvement of load and line regulations.