公开(公告)号：US11831303B2

公开(公告)日：2023-11-28

申请号：US17533365

申请日：2021-11-23

Applicant: GaN Systems Inc.

Inventor： Xuechao Liu ,  Ruoyu Hou

IPC: H03K17/082 ,  H02M1/00 ,  H02M1/32 ,  H01L29/20 ,  H02M3/335 ,  H03K17/08

CPC classification number: H03K17/0822 ,  H01L29/2003 ,  H02M1/0009 ,  H02M1/32 ,  H02M3/33569 ,  H03K2017/0806 ,  H03K2217/0027

Abstract: High accuracy current sense circuitry for power switching devices comprising GaN power transistors provides for current feedback functions, e.g. current loop control, over-current protection (OCP) and short-circuit protection (SCP). The current sense circuitry comprises a current mirror sense GaN transistor (Sense_GaN) and a power GaN transistor (Power_GaN) and a sampling circuit. The sampling circuit comprises first and second stage operational amplifiers to provide fast response and improved current sense accuracy, e.g. better than 1%, over a range of junction temperatures Tj. The Sense_GaN, Power_GaN and first stage operational amplifier have a common ground referenced to a Kelvin Source of the Power_GaN, so that the Sense_GaN and Power_GaN operate with the same gate-to-source voltage Vgs, to provide an accurate current ratio. Applications include current sensing for switching mode power supplies that need high speed and lossless current sense for current protection and feedback.

公开(公告)号：US11736100B2

公开(公告)日：2023-08-22

申请号：US17308423

申请日：2021-05-05

Applicant: GaN Systems Inc.

Inventor： Ruoyu Hou ,  Juncheng Lu ,  Larry Spaziani

IPC: H03K17/0812 ,  H03K17/16

CPC classification number: H03K17/08122 ,  H03K17/163

Abstract: An active gate voltage control circuit for a gate driver of a power semiconductor switching device comprising a power semiconductor transistor, such as a GaN HEMT, provides active gate voltage control comprising current burst mode operation and protection mode operation. The gate-source turn-on voltage Vgs(on) is increased in burst mode operation, to allow for a temporary increase of saturation current. In protection mode operation, a multi-stage turn-off may be implemented, comprising reducing Vgs(on) to implement fast soft turn-off, followed by full turn-off to bring Vgs(on) below threshold voltage, to reduce switching transients such as Vds spikes. Circuits of example embodiments provide for burst mode operation for enhanced saturation current, to increase robustness of enhancement mode GaN power switching devices, e.g. under overcurrent and short circuit conditions, or to provide active gate voltage control which adjusts dynamically to specific operating conditions or events.