LOSSLESS EXCITING CURRENT SAMPLING CIRCUIT FOR ISOLATED CONVERTER

    公开(公告)号:US20250085315A1

    公开(公告)日:2025-03-13

    申请号:US18567382

    申请日:2022-12-29

    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.

    ENHANCEMENT-MODE N-CHANNEL AND P-CHANNEL GAN DEVICE INTEGRATION STRUCTURE

    公开(公告)号:US20240266430A1

    公开(公告)日:2024-08-08

    申请号:US18577714

    申请日:2022-12-29

    CPC classification number: H01L29/7787 H01L29/1066 H01L29/2003 H01L29/207

    Abstract: An enhancement-mode N-channel and P-channel GaN device integration structure comprises a substrate, wherein an Al—N nucleating layer, an AlGaN buffer layer, a GaN channel layer and an AlGaN barrier layer are sequentially arranged on the substrate, and the AlGaN barrier layer and the GaN channel layer are divided by an isolation layer; a P-channel device is arranged on one side of the isolation layer and comprises a first P-GaN layer, a first GaN isolation layer and a first P+-GaN layer are sequentially arranged on the first P-GaN layer, a first source, a first gate and a first drain are arranged on the first P+-GaN layer, the first gate is inlaid in the first P+-GaN layer, and a gate dielectric layer is arranged between the first gate and the first P+-GaN layer; and an N-channel device is arranged on the other side of the isolation layer.

    CONTROL METHOD FOR FOUR-SWITCH BUCK-BOOST CONVERTER

    公开(公告)号:US20240266959A1

    公开(公告)日:2024-08-08

    申请号:US18566102

    申请日:2022-09-26

    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.

    SELF-ADAPTIVE SYNCHRONOUS RECTIFICATION CONTROL SYSTEM AND METHOD OF ACTIVE CLAMP FLYBACK CONVERTER

    公开(公告)号:US20210194375A1

    公开(公告)日:2021-06-24

    申请号:US16617508

    申请日:2018-09-28

    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.

    GRAPHENE CHANNEL SILICON CARBIDE POWER SEMICONDUCTOR TRANSISTOR

    公开(公告)号:US20210336009A1

    公开(公告)日:2021-10-28

    申请号:US16486494

    申请日:2018-09-25

    Abstract: The invention provides a graphene channel silicon carbide power semiconductor transistor, and its cellular structure thereof. Characterized in that, a graphene strip serving as a channel is embedded in a surface of the P-type body region and two ends of the graphene strip are respectively contacted with a boundary between the N+-type source region and the P-type body region and a boundary between the P-type body region and the N-type drift region, and the graphene strip is distributed in a cellular manner in a gate width direction, a conducting channel of a device is still made of graphene; in the case of maintaining basically invariable on-resistance and current transmission capacity, the P-type body regions are separated by the graphene strip, thus enhancing a function of assisting depletion, which further reduces an overall off-state leakage current of the device, and improves a breakdown voltage.

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