• Journal of IKEEE
• /
• v.23 no.2
• /
• pp.552-556
• /
• 2019

This paper present a capless low drop out regulator (LDO) that improves the load transient response characteristics by using a current regulator. A voltage regulator circuit is placed between the error amplifier and the pass transistor inside the LDO regulator to improve the current characteristics of the voltage line, The proposed fast transient LDO structure was designed by a 0.18 um process with cadence's virtuoso simulation. according to test results, the proposed circuit has a improved transient characteristics compare with conventional LDO. the simulation results show that the transient of rising increases from 1.954 us to 1.378 us and the transient of falling decreases from 19.48 us to 13.33 us compared with conventional capless LDO. this Result has improved response rate of about 29%, 28%.

• Journal of IKEEE
• /
• v.26 no.1
• /
• pp.124-128
• /
• 2022

Conventional LDO regulator external capacitors can reduce transient response characteristics such as overshoot and undershoot. However, the capacitorless LDO regulator proposed in this study applied body technology to the pass transistor to improve the transient response and provide excellent current drive capability. The operating conditions of the proposed LDO regulator are set to an input voltage that varies from 3.3V to 4.5V, a maximum load current of 200mA, and an output voltage of 3V. As a result of the measurement, it was found that when the load current was 100 mA, the voltage was 95 mV in the undershoot state and 105 mV in the overshoot state.

• Journal of Power Electronics
• /
• v.17 no.2
• /
• pp.315-322
• /
• 2017

LED is a promising new generation of green lighting with the advantages of high efficiency, good optical performance, long lifetime and environmental friendliness. A pulsating current can be used to drive LEDs. However, current with a high peak-to-average ratio is unfavorable for LEDs. A novel control scheme for the ac-dc critical conduction mode (CRM) flyback LED driver is proposed in this paper. By using the input voltage, output voltage and average output current to control the turn-on time of the switch, the peak-to-average ratio of the output current can be reduced. The operation principle is analyzed and an implementation circuit is put forward. Experimental results show the effectiveness of the proposed scheme.

• Journal of IKEEE
• /
• v.24 no.4
• /
• pp.1162-1166
• /
• 2020

In this paper Low Drop-Out (LDO) regulator that improved load regulation characteristics due to the feedback detection structure. The proposed feedback sensing circuit is added between the output of the LDO's internal error amplifier and the input of the pass transistor to improve the regulation of the delta value coming into the output. It has a voltage value with improved load regulation characteristics than existing LDO regulator. The proposed LDO structure was analyzed in Samsung 0.13um process using Cadence's Virtuoso, Spectre simulator.

• Proceedings of the KIPE Conference
• /
• 2020.08a
• /
• pp.163-165
• /
• 2020

본 논문에서는 전해 커패시터 없이 DC충전이 가능한 단상/3상 겸용 전기자동차용 탑재형 충전기를 제안한다. 제안하는 충전기는 전해커패시터를 제거하고 필름 커패시터를 사용하여 높은 수명 및 전력밀도를 기대할 수 있으며, 단일단(Single-stage) 구조로서 스위칭 개수가 적어 가격 절감에 유리하다. 제안하는 Single-stage OBC는 기존 Single-stage OBC의 단상동작에서 발생하는 배터리 측의 120Hz 전류 성분을 추가 스위칭 소자 없이 APD(Active Power Decoupling)회로로 제거하여 단상에서도 배터리에 DC충전이 가능하다. 본 논문에서는 제안하는 OBC와 APD 동작원리를 제시하고 11kW 시작품을 통해 타당성을 검증하였다.

• Proceedings of the KIPE Conference
• /
• 2020.08a
• /
• pp.25-27
• /
• 2020

본 논문은 단상/3상 겸용 단일단 800V 전기차 탑재형 충전기를 제안한다. 제안하는 단일단 충전기는 넓은 단상/3상의 계통전압(120V-240V)에도 스위치의 ZVS 턴 온을 보장하며 전해 콘덴서 없이 DC충전이 가능하다. 2상 인터리브드 토템폴 구조로 구성되어 입력필터가 작으며 전해콘덴서가 없어서 5.5kW/L의 높은 전력밀도를 달성하였다. 또한 4차 고조파 주입 알고리즘을 통해 고조파 규정인 EN 61000-3-2 규정을 만족한다. 시작품의 타당성 및 성능 검증을 위해 SiC 소자를 적용하여 스위칭 주파수 150kHz의 11kW급 충전기를 제작하였고 제안하는 컨버터의 타당성 및 성능을 검증하였다.

• Journal of IKEEE
• /
• v.24 no.2
• /
• pp.598-603
• /
• 2020

In this paper present a Low Drop-Out(LDO) regulator that improves load transient characteristics due to the push-pull pass transistor structure is proposed. Improved load over the existing LDO regulator by improving the overshoot and undershoot entering the voltage line by adding the proposed push-pull circuit between the output stage of the error amplifier inside the LDO regulator and the gate stage of the pass transistor and the push-pull circuit at the output stage. It has a delta voltage value of transient characteristics. The proposed LDO structure was analyzed in Samsung 0.13um process using Cadence's Virtuoso, Spectre simulator.

• Journal of IKEEE
• /
• v.25 no.3
• /
• pp.506-510
• /
• 2021

In this paper, we propose an LDO that improves the load regulation change due to the current detection structure. The proposed LDO regulator adds the proposed current detection circuit to the output stage. Thereby to improve the load regulation of the delta value coming in on the output has a voltage value of an improved load Regulation characteristics than conventional LDO regulator. Using the proposed current detection structure, it was possible to improve the output change according to the change of the load current by about 60%. The proposed circuit has been simulated and verified characteristics by using a Spectre, Virtuoso simulation of Cadence.