Patents by Inventor Sanjay Havanur

Sanjay Havanur 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: 11824523
    Abstract: Semiconductor device with multiple independent gates. A gate-controlled semiconductor device includes a first plurality of cells of the semiconductor device configured to be controlled by a primary gate, and a second plurality of cells of the semiconductor device configured to be controlled by an auxiliary gate. The primary gate is electrically isolated from the auxiliary gate, and sources and drains of the semiconductor device are electrically coupled in parallel. The first and second pluralities of cells may be substantially identical in structure.
    Type: Grant
    Filed: December 23, 2021
    Date of Patent: November 21, 2023
    Assignee: Vishay-Siliconix, LLC
    Inventors: Sanjay Havanur, M. Ayman Shibib
  • Publication number: 20220123740
    Abstract: Semiconductor device with multiple independent gates. A gate-controlled semiconductor device includes a first plurality of cells of the semiconductor device configured to be controlled by a primary gate, and a second plurality of cells of the semiconductor device configured to be controlled by an auxiliary gate. The primary gate is electrically isolated from the auxiliary gate, and sources and drains of the semiconductor device are electrically coupled in parallel. The first and second pluralities of cells may be substantially identical in structure.
    Type: Application
    Filed: December 23, 2021
    Publication date: April 21, 2022
    Inventors: Sanjay Havanur, M. Ayman Shibib
  • Patent number: 11218144
    Abstract: Semiconductor device with multiple independent gates. A gate-controlled semiconductor device includes a first plurality of cells of the semiconductor device configured to be controlled by a primary gate, and a second plurality of cells of the semiconductor device configured to be controlled by an auxiliary gate. The primary gate is electrically isolated from the auxiliary gate, and sources and drains of the semiconductor device are electrically coupled in parallel. The first and second pluralities of cells may be substantially identical in structure.
    Type: Grant
    Filed: September 12, 2019
    Date of Patent: January 4, 2022
    Assignee: Vishay-Siliconix, LLC
    Inventors: Sanjay Havanur, M. Ayman Shibib
  • Publication number: 20210083660
    Abstract: Semiconductor device with multiple independent gates. A gate-controlled semiconductor device includes a first plurality of cells of the semiconductor device configured to be controlled by a primary gate, and a second plurality of cells of the semiconductor device configured to be controlled by an auxiliary gate. The primary gate is electrically isolated from the auxiliary gate, and sources and drains of the semiconductor device are electrically coupled in parallel. The first and second pluralities of cells may be substantially identical in structure.
    Type: Application
    Filed: September 12, 2019
    Publication date: March 18, 2021
    Inventors: Sanjay Havanur, M. Ayman Shibib
  • Patent number: 10622994
    Abstract: A driver for a semiconductor switching device can be configured to step down a supply voltage to generate a first drive voltage. The driver can also generate a second drive voltage equal to the potential difference between the supply voltage and the first drive voltage. The driver can supply the first drive voltage to a control gate of the semiconductor switching device during a first state of a control signal, and a reverse polarity of the second drive voltage during a second state of the control signal.
    Type: Grant
    Filed: June 7, 2018
    Date of Patent: April 14, 2020
    Assignee: Vishay-Siliconix, LLC
    Inventor: Sanjay Havanur
  • Publication number: 20190379375
    Abstract: A driver for a semiconductor switching device can be configured to step down a supply voltage to generate a first drive voltage. The driver can also generate a second drive voltage equal to the potential difference between the supply voltage and the first drive voltage.
    Type: Application
    Filed: June 7, 2018
    Publication date: December 12, 2019
    Inventor: Sanjay HAVANUR
  • Patent number: 8633512
    Abstract: A circuit is proposed for limiting maximum switching FET drain-source voltage (VDS) of a transformer-coupled push pull power converter with maximum DC supply voltage VIN—MAX. Maximum VDS is accentuated by leakage inductances of the push pull transformer and the power converter circuit traces. The limiting circuit bridges the drains of the switching FETs and it includes two serially connected opposing Zener diodes each having a Zener voltage Vzx. The invention is applicable to both N-channel and P-channel FETs. In a specific embodiment, Vzx is selected to be slightly ?2*VIN—MAX with the maximum VDS clamped to about VIN—MAX+½Vzx. In another embodiment, a proposed power switching device with integrated VDS-clamping includes a switching FET; and a Zener diode having a first terminal and a second terminal, the second terminal of the Zener diode is connected to the drain terminal of the switching FET.
    Type: Grant
    Filed: April 24, 2012
    Date of Patent: January 21, 2014
    Assignee: Alpha & Omega Semiconductor, Inc.
    Inventor: Sanjay Havanur
  • Patent number: 8264861
    Abstract: A circuit is proposed for limiting maximum switching FET drain-source voltage (VDS) of a transformer-coupled push pull power converter with maximum DC supply voltage VIN—MAX. Maximum VDS is accentuated by leakage inductances of the push pull transformer and the power converter circuit traces. The limiting circuit bridges the drains of the switching FETs and it includes two serially connected opposing Zener diodes each having a Zener voltage Vzx. The invention is applicable to both N-channel and P-channel FETs. In a specific embodiment, Vzx is selected to be slightly ?2*VIN—MAX with the maximum VDS clamped to about VIN—MAX+½Vzx. In another embodiment, a proposed power switching device with integrated VDS clamping includes: In another embodiment, a proposed power switching device with integrated VDS-clamping includes a switching FET; and a Zener diode having a first terminal and a second terminal, the second terminal of the Zener diode is connected to the drain terminal of the switching FET.
    Type: Grant
    Filed: February 25, 2011
    Date of Patent: September 11, 2012
    Assignee: Alpha & Omega Semiconductor, Inc.
    Inventor: Sanjay Havanur
  • Publication number: 20120205745
    Abstract: A circuit is proposed for limiting maximum switching FET drain-source voltage (VDS) of a transformer-coupled push pull power converter with maximum DC supply voltage VIN—MAX. Maximum VDS is accentuated by leakage inductances of the push pull transformer and the power converter circuit traces. The limiting circuit bridges the drains of the switching FETs and it includes two serially connected opposing Zener diodes each having a Zener voltage Vzx. The invention is applicable to both N-channel and P-channel FETs. In a specific embodiment, Vzx is selected to be slightly ?2*VIN—MAX with the maximum VDS clamped to about VIN—MAX +½Vzx. In another embodiment, a proposed power switching device with integrated VDS-clamping includes a switching FET; and a Zener diode having a first terminal and a second terminal, the second terminal of the Zener diode is connected to the drain terminal of the switching FET.
    Type: Application
    Filed: April 24, 2012
    Publication date: August 16, 2012
    Inventor: Sanjay Havanur
  • Patent number: 8207017
    Abstract: A method of fabricating a stacked dual MOSFET die package is disclosed. The method includes the steps of (a) forming a first conductive tab, (b) stacking a high side MOSFET die on the first conductive tab such that a drain contact of the high side MOSFET die is coupled to the first conductive tab, (c) stacking a second conductive tab in overlaying relationship to the high side MOSFET die such that a source contact of the high side MOSFET die is coupled to the second conductive tab, and (d) stacking a low side MOSFET die on the second conductive tab such that a drain contact of the low side MOSFET die is coupled to the second conductive tab.
    Type: Grant
    Filed: October 29, 2008
    Date of Patent: June 26, 2012
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventor: Sanjay Havanur
  • Patent number: 7999600
    Abstract: A circuit for limiting di/dt caused by a main switching FET during its turn-off against an inductive switching circuit is proposed. The circuit for limiting di/dt includes an auxiliary inductor in series with the main switching FET for inducing an auxiliary inductive voltage proportional to di/dt; an auxiliary FET in parallel with the main switching FET; the auxiliary FET gate is connected to produce a gate voltage equal to the auxiliary inductive voltage. When the di/dt tends to exceed a predetermined maximum rate of decrease the auxiliary FET produces an auxiliary current component counteracting further decrease of the di/dt. The main switching FET and the auxiliary FET can be formed from a single die with shared source and drain; the auxiliary inductor can be implemented as a parasitic inductance of an inherently required bonding wire connecting the main switching FET to its device terminal to simplify packaging with reduced cost.
    Type: Grant
    Filed: June 5, 2009
    Date of Patent: August 16, 2011
    Assignee: Alpha and Omega Semiconductor, Inc.
    Inventor: Sanjay Havanur
  • Publication number: 20110149620
    Abstract: A circuit is proposed for limiting maximum switching FET drain-source voltage (VDS) of a transformer-coupled push pull power converter with maximum DC supply voltage VIN—MAX. Maximum VDS is accentuated by leakage inductances of the push pull transformer and the power converter circuit traces. The limiting circuit bridges the drains of the switching FETs and it includes two serially connected opposing Zener diodes each having a Zener voltage Vzx. The invention is applicable to both N-channel and P-channel FETs. In a specific embodiment, Vzx is selected to be slightly ?2*VIN—MAX with the maximum VDS clamped to about VIN—MAX+½Vzx, In another embodiment, a proposed power switching device with integrated VDS-clamping includes: a) A switching FET. b) A Zener diode having a first terminal and a second terminal, the second terminal of the Zener diode is connected to the drain terminal of the switching FET.
    Type: Application
    Filed: February 25, 2011
    Publication date: June 23, 2011
    Inventor: Sanjay Havanur
  • Patent number: 7898831
    Abstract: A circuit is proposed for limiting maximum switching FET drain-source voltage (VDS) of a transformer-coupled push pull power converter with maximum DC supply voltage VIN—MAX. Maximum VDS is accentuated by leakage inductances of the push pull transformer and the power converter circuit traces. The limiting circuit bridges the drains of the switching FETs and it includes two serially connected opposing Zener diodes each having a Zener voltage Vzx. The invention is applicable to both N-channel and P-channel FETs. In a specific embodiment, Vzx is selected to be slightly ?2*VIN—MAX with the maximum VDS clamped to about VIN—MAX+½ Vzx. In another embodiment, a proposed power switching device with integrated VDS-clamping includes: a) A switching FET. b) A Zener diode having a first terminal and a second terminal, the second terminal of the Zener diode is connected to the drain terminal of the switching FET.
    Type: Grant
    Filed: May 9, 2008
    Date of Patent: March 1, 2011
    Assignee: Alpha and Omega Semiconductor Inc.
    Inventor: Sanjay Havanur
  • Patent number: 7876584
    Abstract: A secondary FETsc control circuit is disclosed for controlling FETsc of transformer coupled synchronous rectified flyback converter (TCSC). The control circuit includes source-drain voltage VSD sense trigger with output VSD-trigger activated upon positive 0-crossing of VSD. Drain-source current IDS sense trigger with output IDS-trigger activated upon positive 0-crossing of IDS. Secondary coil voltage Vsec sense trigger with output Vsec-trigger activated upon sensing negative Vsec. A multi-trigger gate driver (MTGD) has trigger inputs coupled to VSD-trigger, IDS-trigger, Vsec-trigger and drive output driving the FETsc gate. The MTGD has logic states of state-I where FETsc is turned off and latched, state-II where FETsc is turned off but unlatched, state-III where FETsc is turned on but unlatched. The MTGD is configured to enter state-III upon VSD-trigger, enter state-I upon IDS-trigger and enter state-IT upon Vsec-trigger.
    Type: Grant
    Filed: June 24, 2009
    Date of Patent: January 25, 2011
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventor: Sanjay Havanur
  • Publication number: 20100327947
    Abstract: A secondary FETsc control circuit is disclosed for controlling FETsc of transformer coupled synchronous rectified flyback converter (TCSC). The control circuit includes source-drain voltage VSD sense trigger with output VSD-trigger activated upon positive 0-crossing of VSD. Drain-source current IDS sense trigger with output IDS-trigger activated upon positive 0-crossing of IDS. Secondary coil voltage Vsec sense trigger with output Vsec-trigger activated upon sensing negative Vsec. A multi-trigger gate driver (MTGD) has trigger inputs coupled to VSD-trigger, IDS-trigger, Vsec-trigger and drive output driving the FETsc gate. The MTGD has logic states of state-I where FETsc is turned off and latched, state-II where FETsc is turned off but unlatched, state-III where FETsc is turned on but unlatched. The MTGD is configured to enter state-III upon VSD-trigger, enter state-I upon IDS-trigger and enter state-IT upon Vsec-trigger.
    Type: Application
    Filed: June 24, 2009
    Publication date: December 30, 2010
    Inventor: Sanjay Havanur
  • Patent number: 7671662
    Abstract: A semiconductor power device includes a circuit to provide a gate signal wherein the gate signal has a negative temperature coefficient of gate driving voltage for decreasing a gate driving voltage with an increase temperature whereby the semiconductor power device has a net Ids temperature coefficient that is less than or equal to zero. In an exemplary embodiment, the gate voltage driver includes a diode that has a negative forward voltage temperature coefficient connected between a gate and a source of the semiconductor power device. In another embodiment, the gate voltage is integrated with the semiconductor power device manufactured as part of an integrated circuit with the semiconductor power device.
    Type: Grant
    Filed: October 28, 2008
    Date of Patent: March 2, 2010
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Sik K Lui, Anup Bhalla, Sanjay Havanur
  • Publication number: 20090279330
    Abstract: A circuit is proposed for limiting maximum switching FET drain-source voltage (VDS) of a transformer-coupled push pull power converter with maximum DC supply voltage VIN—MAX. Maximum VDS is accentuated by leakage inductances of the push pull transformer and the power converter circuit traces. The limiting circuit bridges the drains of the switching FETs and it includes two serially connected opposing Zener diodes each having a Zener voltage Vzx. The invention is applicable to both N-channel and P-channel FETs. In a specific embodiment, Vzx is selected to be slightly ?2*VIN—MAX with the maximum VDS clamped to about VIN—MAX+½ Vzx. In another embodiment, a proposed power switching device with integrated VDS-clamping includes: a) A switching FET. b) A Zener diode having a first terminal and a second terminal, the second terminal of the Zener diode is connected to the drain terminal of the switching FET.
    Type: Application
    Filed: May 9, 2008
    Publication date: November 12, 2009
    Inventor: Sanjay Havanur
  • Publication number: 20090243715
    Abstract: A circuit for limiting di/dt caused by a main switching FET during its turn-off against an inductive switching circuit is proposed. The circuit for limiting di/dt includes: An auxiliary inductor in series with the main switching FET for inducing an auxiliary inductive voltage proportional to di/dt. An auxiliary FET in parallel with the main switching FET. The auxiliary FET gate is connected to produce a gate voltage equal to the auxiliary inductive voltage. When the di/dt tends to exceed a pre-determined maximum rate of decrease, the auxiliary FET produces an auxiliary current component counteracting further decrease of the di/dt. The main switching FET and the auxiliary FET can be formed from a single die with shared source and drain. The auxiliary inductor can be implemented as a parasitic inductance of an inherently required bonding wire connecting the main switching FET to its device terminal to simplify packaging with reduced cost.
    Type: Application
    Filed: June 5, 2009
    Publication date: October 1, 2009
    Inventor: Sanjay Havanur
  • Patent number: 7564292
    Abstract: A circuit for limiting di/dt caused by a main switching FET during its turn-off against an inductive switching circuit is proposed. The circuit for limiting di/dt includes: An auxiliary inductor in series with the main switching FET for inducing an auxiliary inductive voltage proportional to di/dt. An auxiliary FET in parallel with the main switching FET. The auxiliary FET gate is connected to produce a gate voltage equal to the auxiliary inductive voltage. When the di/dt tends to exceed a pre-determined maximum rate of decrease, the auxiliary FET produces an auxiliary current component counteracting further decrease of the di/dt. The main switching FET and the auxiliary FET can be formed from a single die with shared source and drain. The auxiliary inductor can be implemented as a parasitic inductance of an inherently required bonding wire connecting the main switching FET to its device terminal to simplify packaging with reduced cost.
    Type: Grant
    Filed: September 28, 2007
    Date of Patent: July 21, 2009
    Assignee: Alpha & Omega Semiconductor, Inc.
    Inventor: Sanjay Havanur
  • Publication number: 20090130799
    Abstract: A method of fabricating a stacked dual MOSFET die package is disclosed. The method includes the steps of (a) forming a first conductive tab, (b) stacking a high side MOSFET die on the first conductive tab such that a drain contact of the high side MOSFET die is coupled to the first conductive tab, (c) stacking a second conductive tab in overlaying relationship to the high side MOSFET die such that a source contact of the high side MOSFET die is coupled to the second conductive tab, and (d) stacking a low side MOSFET die on the second conductive tab such that a drain contact of the low side MOSFET die is coupled to the second conductive tab.
    Type: Application
    Filed: October 29, 2008
    Publication date: May 21, 2009
    Inventor: Sanjay Havanur