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Your search keyword '"Lee, Myunghee"' showing total 2 results
Start Over Author "Lee, Myunghee" Topic dc-to-dc converters Publication Year Range Last 50 years
2 results on '"Lee, Myunghee"'

1. A 15 – 25-MHz and 1- μ s/0.4-A Load Response AOT Boost Converter Using an Accurate Feedforward-Path Current Sensor.

Author

Hong, Woojin and Lee, Myunghee

Subjects
*COMPLEMENTARY metal oxide semiconductors, *DETECTORS, *ADAPTIVE control systems, *DC-to-DC converters, *LOGIC circuits, *TRANSIENT responses (Electric circuits)
Abstract

This letter presents a high-frequency boost converter using an accurate feedforward-path current sensor for the fast-load transient response. To operate with the switching frequency of up to 25 MHz, the proposed current sensor senses the inductor current with a fast-sensing response time of about 4.5 ns. It also provides more accurate sensing gain than previous current sensors. In addition, the adaptive on-time control method is used for the proposed converter to further enhance the transient responses. The converter has been fabricated using a 0.18-μm CMOS process with a total chip area of 1.3 × 1.12 mm. It achieves a fast-load transient of only 1 μs at a 400-mA load step, and peak efficiency of 91.5 and 88.2% at switching frequencies of 15 and 25 MHz, respectively. [ABSTRACT FROM AUTHOR]

Published
2022
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2. A 7.4-MHz Tri-Mode DC-DC Buck Converter With Load Current Prediction Scheme and Seamless Mode Transition for IoT Applications.

Author

Hong, Woojin and Lee, Myunghee

Subjects
*DC-to-DC converters, *FORECASTING, *COMPLEMENTARY metal oxide semiconductors, *PULSE frequency modulation, *PRINTED circuits, *CASCADE converters, *PRINTED circuit design
Abstract

The growth of IoT applications requires DC-DC converters to have small printed circuit board (PCB) areas and high efficiency over a wide load range. A multi-mode operation of DC-DC converters, therefore, is often necessary to achieve this high efficiency over a wide load range. This paper introduces a tri-mode DC-DC buck converter for IoT applications. The tri-mode operation with PWM, PFM, and multiple-sawtooth PWM (MSPWM) modes helps to retain the high efficiency over the wide load range. The MSPWM mode also enhances a noise margin of the converter, ensuring a regular switching operation at an ultra-light load condition. With a load current prediction scheme, the proposed tri-mode converter requires neither additional load current sensor nor multiple mode controllers. In addition, a soft-start operation is employed to prevent an in-rush current. The proposed tri-mode buck converter has been fabricated through a 0.18- $\mu \text{m}$ CMOS process with a chip area of 0.97 mm $\times0.88$ mm. A load-dependent seamless mode transition is realized, and a maximum converter efficiency of 91% has been measured with a 7.4-MHz switching frequency. [ABSTRACT FROM AUTHOR]

Published
2020
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