Browsing by Author "Shih, Chun-Jen"

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A Power Cloud System (PCS) for High Efficiency and Enhanced Transient Response in SoC
(2013-03-01)
Shih, Chun-Jen
;
Chu, Kuan-Yu
;
Lee, Yu-Huei
;
Chen, Wei-Chung
;
Luo, Hsin-Yu
Tradeoff between power efficiency and transient performance usually comes out during the design consideration of a power module. A configurable power supplying implementation named as the power cloud system (PCS) is proposed to handle different load conditions for simultaneously improving the power efficiency and the transient response in order to meet the system-on-chip (SoC) requirements. At heavy loads, the switching regulator takes over the energy delivery scheme in the PCS with the fast transient technique. An auxiliary power unit, which activates hybrid operation in both medium and light loads, can realize the low-dropout (LDO) regulator to provide a supplementary energy immediately in transient duration and be the high-side power switches of the switching regulator to minimize the power loss. Besides, owing to its low quiescent current of an LDO regulator, it can directly operate under the ultralight-load condition. Therefore, the satisfactory power conversion efficiency and the load transient response can be derived over a wide load range, which will certainly meet the power requirement for different operated functions in the SoC. The chip was fabricated by a 0.25-mu m CMOS process, and the experimental results show the improvements of 56% transient dip voltage and 25% transient recovery time in hybrid operation, as well as a peak efficiency of 94%.
A Single-Inductor Bipolar-Output Converter with 5 mV Positive Voltage Ripple for Active Matrix OLED
(2011)
Chen, Wei-Chung
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Chiu, Chao-Chang
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Hsieh, Chun-Yu
;
Huang, Tzu-Chi
;
Lee, Yu-Huei
This paper proposed a single inductor bipolar outputs (SIBO) switching converter for the active matrix Organic Light-Emitting Diode (AMOLED). The negative voltage is generated by the inverting buck-boost converter, which is regulated by the high signal-to-noise ratio comparator. Moreover, the boost converter is utilized to provide the positive output voltage. The proposed switching converter uses the switch sequential to reduce the positive voltage ripple to about 5 mV with the proportional-integral (PI) compensator to guarantee good line and load-regulation. Simulation results show the positive output voltage is regulated to 5V and the negative output voltage is -7V for driving the AMOLED. When the load current is 25 mA and the ESR is 30m Omega, the output voltage ripples are equal to 5 mV and 11 mV for positive and negative voltages, respectively. Besides, the load and line regulations of positive output voltage are 0.24 mV/mA and 5 mV/V, respectively. The maximum efficiency is 88.5% when the input voltage is 4.5 V and the load current is 50mA
Proportional Compensated Buck Converter With a Differential-In Differential-Out (DIDO) Error Amplifier and Load Regulation Enhancement (LRE) Mechanism
(2012-05-01)
Lee, Yu-Huei
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Chu, Kuan-Yu
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Shih, Chun-Jen
;
Chen, Ke-Horng
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電控工程研究所
A differential-in differential-out error amplifier and a load regulation enhancement mechanism are proposed in the buck converter that aims to improve load regulation and noise immunity. By using the proportional compensator in the proposed converter, there is no need of external compensation components in this design. As a result, a compact-size and high-performance dc-dc buck converter can be guaranteed. Experimental results show that load regulation can be improved from 0.5 to 0.025 mV/mA. The test chip was fabricated by 0.25 mu m CMOS process and occupied 1.65 mm(2) active silicon area.
Single Controller Current Balance (SCCB) Technique for Voltage-Mode Multi-Phase Buck Converter
(2011)
Huang, Yu-Ping
;
Su, Yi-Ping
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Lee, Yu-Huei
;
Chu, Kuan-Yu
;
Shih, Chun-Jen
a single controller current balance (SCCB) technique is proposed to achieve the time-multiplexing current balance in voltage-mode multi-phase DC-DC buck converter with only one modulation controller. Thus, the N-1 controllers can be removed when the SCCB technique is implemented in the monolithic N-phase DC-DC buck converters for largely decreasing the silicon area and power consumption. In addition, the time-multiplexing current balance scheme can further enhance the current sharing accuracy since the mismatches between different controllers does not exist. Simulated results show that the current difference between each phase can be decreased by over 80 % at both heavy load and light load conditions.