公开(公告)号：US20180262186A1

公开(公告)日：2018-09-13

申请号：US15779432

申请日：2017-01-23

Applicant: SOUTHEAST UNIVERSITY ,  SOUTHEAST UNIVERSITY-WUXI INTEGRATED CIRCUIT TECHNOLOGY RESEARCH INSTITUTE

Inventor： Weifeng SUN ,  Yunwu ZHANG ,  Kuo YU ,  Jing ZHU ,  Shen XU ,  Qinsong QIAN ,  Siyang LIU ,  Shengli LU ,  Longxing SHI

IPC: H03K17/06 ,  H03K17/687 ,  H03K17/16

CPC classification number: H03K17/063 ,  H01L27/0727 ,  H01L29/1083 ,  H01L29/42368 ,  H01L29/7835 ,  H03K17/162 ,  H03K17/6871 ,  H03K19/0185 ,  H03K2217/0063 ,  H03K2217/0081

Abstract: Parasitic high-voltage diodes implemented by integration technology in a high-voltage level shift circuit are used for charging a bootstrap capacitor CB, wherein a power supply end of the high voltage level shift circuit is a high-side floating power supply VB, and a reference ground is a floating voltage PGD that is controlled by a bootstrap control circuit. A first parasitic diode DB1 and a second parasitic diode DB2 are provided between the VB and the PGD. The bootstrap control circuit is controlled by a high-side signal and a low-side signal.

公开(公告)号：US20200336076A1

公开(公告)日：2020-10-22

申请号：US16959116

申请日：2018-12-29

Applicant: CSMC TECHNOLOGIES FAB2 CO., LTD. ,  SOUTHEAST UNIVERSITY

Inventor： Qinsong QIAN ,  Shengyou XU ,  Feng LIN ,  Hao WANG ,  Wei SU ,  Qi LIU ,  Longxing SHI

IPC: H02M3/335

Abstract: A control system for synchronous rectifying transistor of LLC converter, the system comprising a voltage sampling circuit, a high-pass filtering circuit, a PI compensation and effective value detection circuit, and a control system taking a microcontroller (MCU) as a core. When the LLC converter is operating at a high frequency, a drain-source voltage VDS(SR) of the synchronous rectifying transistor delivers, via the sampling circuit, a change signal of the drain-source voltage during turn-off into the high-pass filtering circuit and the PI compensation and effective value detection circuit to obtain an effective value amplification signal of a drain-source voltage oscillation signal caused by parasitic parameters, and the current value is compared with a previously collected value via a control circuit taking a microcontroller (MCU) as a core, so as to change a turning-on time of the synchronous rectifying transistor in the next period.

公开(公告)号：US20250085315A1

公开(公告)日：2025-03-13

申请号：US18567382

申请日：2022-12-29

Applicant: SOUTHEAST UNIVERSITY

Inventor： Qinsong QIAN ,  Song DING ,  Chunyan NIE ,  Yuanhang ZHOU ,  Weifeng SUN ,  Longxing SHI

IPC: G01R19/00 ,  H02M1/00 ,  H02M3/335

Abstract: A lossless exciting current sampling circuit for an isolated converter includes first and second voltage sampling circuits and a subtraction circuit formed by an operational amplifier. The two sampling circuits sample voltages of the primary winding of an isolation transformer, with outputs fed into the subtracter. The subtracter output is the circuit's output. RC low-pass filters with large time constants are used as primary voltage sampling circuits, realizing integration of voltage differences between the exciting inductance terminals, enabling lossless current sampling without resistors or transformers. The current sampling result is utilized for volt-second balance control, realized along with a hold circuit and comparator which compares the sampling hold result with the current sampling result to generate a control signal.

公开(公告)号：US20240266959A1

公开(公告)日：2024-08-08

申请号：US18566102

申请日：2022-09-26

Applicant: SOUTHEAST UNIVERSITY

Inventor： Qi LIU ,  Weiwei ZHAI ,  Leilei SHI ,  Qinsong QIAN ,  Weifeng SUN ,  Longxing SHI

IPC: H02M3/158 ,  H02M1/00 ,  H02M1/088

CPC classification number: H02M3/1582 ,  H02M1/0058 ,  H02M1/088

Abstract: A control method for a four-switch buck-boost converter is provided. The control method adopts four-stage control, and divides the load range into two sections and adopts different control strategies according to a critical load value corresponding to optimal control. In Boost mode, before the critical load, T1 and T2 are kept constant, T3 is a minimum value for realizing soft-switching, and T4 decreases with the increase of the load; when the critical load is reached, T4 drops to 0; and after the critical load, T1, T2, T3 and T increase with the load. In Buck mode, before the critical load, T2 and T3 are kept constant, T1 is a minimum value for realizing soft-switching, and T4 decreases with the increase of the load; when the critical load is reached, T4 drops to 0; and after the critical load, T1, T2, T3 and T increase with the load.

公开(公告)号：US20210194375A1

公开(公告)日：2021-06-24

申请号：US16617508

申请日：2018-09-28

Applicant: SOUTHEAST UNIVERSITY

Inventor： Qinsong QIAN ,  Shengyou XU ,  Qi LIU ,  Weifeng SUN ,  Shengli LU ,  Longxing SHI

IPC: H02M3/335 ,  H02M1/08

Abstract: The invention discloses a self-adaptive synchronous rectification control system and a self-adaptive synchronous rectification control method of an active clamp flyback converter. The control system comprises a sampling and signal processing circuit, a control circuit with a microcontroller as a core and a gate driver. According to the control method, a switching-on state, an early switching-off state, a late switching-off state and an exact switching-off state of a secondary synchronous rectifier of the active clamp flyback converter can be directly detected, and the synchronous rectifier and a switching-on time of the synchronous rectifier in next cycle can be controlled according to a detection result. After several cycles of self-adaptive control, the synchronous rectifier enters the exact switching-on state, thus avoiding oscillation of an output waveform of the active clamp flyback converter.