Fei S Yang, Age 41Lawrenceville, GA

2023007, Mar 9, 2023

Sep 9, 2021

17/470064

- Austin TX, US
Bilal Akin - Richardson TX, US
Shi Pu - Plano TX, US
Fei Yang - Plano TX, US
Masoud Farhadi - Dallas TX, US

G01R 31/26

A system to detect gate-open failures in a MOS based insulated gate transistor can include a detection circuit, including a first circuit configured to measure a drain-source voltage across the MOS based insulated gate transistor, a first comparator circuit can be configured to compare the measured drain-source voltage to a threshold drain-source conduction voltage indicating a conduction state of a channel of the MOS based insulated gate transistor, a second circuit can be configured to measure a gate voltage applied at a gate of the MOS-based insulated gate transistor, a second comparator circuit can be configured to compare the gate voltage applied at the gate to a threshold gate voltage for the MOS based insulated gate transistor to provide an indication of whether the gate voltage applied at the gate is sufficient to activate conduction in the channel and a logic circuit can be configured to detect a gate-open failure of the MOS based insulated gate transistor based on the conduction state of the channel and the indication of whether the gate voltage applied at the gate is sufficient to activate conduction in the channel when the MOS based insulated gate transistor is in an on state or an off state.

2021039, Dec 23, 2021

Jun 23, 2020

16/908997

- Austin TX, US
Fei Yang - Plano TX, US
Shi Pu - Plano TX, US
Chi Xu - Plano TX, US
Bhanu Vankayalapati - Richardson TX, US

G01K 7/00

A method of measuring a junction temperature of a SiC MOSFET can be provided by applying a gate-source voltage to an external gate loop coupled to a gate of the SiC MOSFET, detecting a first time when the gate-source voltage exceeds a first value configured to disable conduction of a current in a drain of the SiC MOSFET, detecting, after the first time, a second time when a voltage across a common source inductance in a package of the SiC MOSFET indicates that the current in the drain is greater than a reference value, defining a time interval from the first time to the second time as a turn on delay time of the SiC MOSFET and determining the junction temperature for the SiC MOSFET using the turn on delay time.

2020040, Dec 31, 2020

Jun 10, 2020

16/897719

- Austin TX, US
Bilal Akin - Richardson TX, US
Fei Yang - Plano TX, US
Shi Pu - Plano TX, US
Chi Xu - Plano TX, US

G01R 31/26

Embodiments according to the invention can provide methods of testing a SiC MOSFET, that can include applying first and second voltage levels across a gate-source junction of a SiC MOSFET and measuring first and second voltage drops across a reverse body diode included in the SiC MOSFET responsive to the first and second voltage levels, respectively, to provide an indication of a degradation of a gate oxide of the SiC MOSFET and an indication of contact resistance of the SiC MOSFET, respectively.

2020040, Dec 24, 2020

Jun 10, 2020

16/897448

- Austin TX, US
Shi Pu - Plano TX, US
Enes Ugur - Plano TX, US
Fei Yang - Plano TX, US
Chi Xu - Plano TX, US
Bhanu Teja Vankayalapati - Richardson TX, US

G01R 31/26

A method of monitoring a condition of a SiC MOSFET can include (a) applying a first test gate-source voltage across a gate-source of a SiC MOSFET in-situ, the first test gate-source voltage configured to operate the SiC MOSFET in saturation mode to generate a first drain current in the SiC MOSFET, (b) applying a second test gate-source voltage across the gate-source of the SiC MOSFET in-situ, the second test gate-source voltage configured to operate the SiC MOSFET in fully-on mode to generate a second drain current in the SiC MOSFET, (c) determining a drain-source saturation resistance using the first drain current to provide an indication of a degradation of a gate oxide of the SiC MOSFET; and (d) determining a drain-source on resistance using the second drain current to provide an indication of a degradation of contact resistance of the SiC MOSFET.