Patents by Inventor Mei Yu Soh

Mei Yu Soh has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 12323143
    Abstract: A GaN logic circuit may include an input node receiving an input voltage, a first pull up transistor pulling up an output voltage in response to the input voltage, and a first depletion mode transistor having a first gate to which a first gate voltage is applied and a second gate to which a second gate voltage is applied. The first depletion mode transistor may control the first pull up transistor in response to a gate voltage difference between the first gate voltage and the second gate voltage. The logic device may further include a capacitor having a first end coupled to the first depletion mode transistor and a second end coupled to the first pull up transistor.
    Type: Grant
    Filed: February 10, 2023
    Date of Patent: June 3, 2025
    Assignee: GlobalFoundries U.S. Inc.
    Inventors: Santosh Sharma, Mei Yu Soh
  • Patent number: 12294364
    Abstract: A circuit structure includes an enhancement mode transistor and a turn-off slew rate controller for automatically adding drain-source capacitance to the transistor when the transistor is transitioning to an off state. The added drain-source capacitance slows the turn-off slew rate (dV/dt_off) of the transistor without also increasing the turn-off energy loss (E_off). The slew rate controller can include: sensors connected to the drain region for sensing both the drain voltage and the slew rate, respectively; a logic circuit for generating and outputting an enable signal based on output voltages from the sensors; and a capacitance adder for adding to the drain-source capacitance only when the logic value of the enable signal indicates that the drain voltage is at or above a predetermined positive drain voltage level and the slew rate is positive.
    Type: Grant
    Filed: August 25, 2023
    Date of Patent: May 6, 2025
    Assignee: GlobalFoundries U.S. Inc.
    Inventors: Santosh Sharma, Mei Yu Soh
  • Publication number: 20250070781
    Abstract: Disclosed circuit structure embodiments include an enhancement mode transistor and a turn-off slew rate controller for automatically adding drain-source capacitance to the transistors when the transistor is transitioning to an off state. The added drain-source capacitance slows the turn-off slew rate (dV/dt_off) of the transistor without also increasing the turn-off energy loss (E_off). In some embodiments, the slew rate controller includes: sensors connected to the drain region for sensing both the drain voltage and the slew rate, respectively; a logic circuit for generating and outputting an enable signal based on output voltages from the sensors; and a capacitance adder for adding to the drain-source capacitance only when the logic value of the enable signal indicates that the drain voltage is at or above a predetermined positive drain voltage level and the slew rate is positive.
    Type: Application
    Filed: August 25, 2023
    Publication date: February 27, 2025
    Inventors: Santosh Sharma, Mei Yu Soh
  • Publication number: 20240275385
    Abstract: A GaN logic circuit may include an input node receiving an input voltage, a first pull up transistor pulling up an output voltage in response to the input voltage, and a first depletion mode transistor having a first gate to which a first gate voltage is applied and a second gate to which a second gate voltage is applied. The first depletion mode transistor may control the first pull up transistor in response to a gate voltage difference between the first gate voltage and the second gate voltage. The logic device may further include a capacitor having a first end coupled to the first depletion mode transistor and a second end coupled to the first pull up transistor.
    Type: Application
    Filed: February 10, 2023
    Publication date: August 15, 2024
    Inventors: Santosh SHARMA, Mei Yu Soh