Patents Assigned to Alpha and Omega Semiconductor (Cayman) LTD
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Patent number: 11756993Abstract: An apparatus comprising an insulated gate bipolar transistor and a super junction metal-oxide semiconductor field effect transistor wherein the insulated gate bipolar transistor and the super-junction metal-oxide semiconductor field effect transistor are electrically and optionally structurally coupled.Type: GrantFiled: May 4, 2022Date of Patent: September 12, 2023Assignee: Alpha and Omega Semiconductor (Cayman) Ltd.Inventors: Madhur Bobde, Lingpeng Guan, Karthik Padmanabhan, Bum-Seok Suh
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Patent number: 11749716Abstract: A semiconductor device includes a semiconductor body having a base region incorporating a field stop zone where the base region and the field stop zone are both formed using an epitaxial process. Furthermore, the epitaxial layer field stop zone is formed with an enhanced doping profile to realize improved soft-switching performance for the semiconductor device. In some embodiments, the enhanced doping profile includes multiple doped regions with peak doping levels where a first doped region adjacent to a first side of the field stop zone has a first peak doping level that is not higher than a last peak doping level of a last doped region adjacent to the base region. The epitaxial layer field stop zone of the present invention enables complex field stop zone doping profiles to be used to obtain the desired soft-switching characteristics in the semiconductor device.Type: GrantFiled: May 4, 2021Date of Patent: September 5, 2023Assignee: Alpha and Omega Semiconductor (Cayman) Ltd.Inventors: Lei Zhang, Karthik Padmanabhan, Lingpeng Guan, Jian Wang, Lingbing Chen, Wim Aarts, Hongyong Xue, Wenjun Li, Madhur Bobde
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Patent number: 11711071Abstract: A current mode control modulation includes a ramp signal generator generating a slope compensated ramp signal with slope compensation. In some embodiments, the ramp signal generator generates a ramp signal for the current control loop having a first ramp portion with slope compensation and a second ramp portion that matches the expected current mode signal. In some embodiments, the ramp signal generator includes a switched capacitor circuit supplied by a current circuit to charge or discharge nodes in the switched capacitor circuit to generate the ramp signal with slope compensation.Type: GrantFiled: November 1, 2021Date of Patent: July 25, 2023Assignee: Alpha and Omega Semiconductor (Cayman) Ltd.Inventors: Nicholas I. Archibald, Rhys S. A. Philbrick, Steven P. Laur
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Patent number: 11664368Abstract: A transient voltage suppressor (TVS) device uses a punch-through silicon controlled rectifier (SCR) structure for the low-side steering diode where the punch-through SCR structure realizes low capacitance at the protected node. In some embodiments, the punch-through silicon controlled rectifier of the low-side steering diode includes a first doped region formed in a first epitaxial layer, a first well formed spaced apart from the first doped region where the first well is not biased to any electrical potential, and a second doped region formed in the first well. The first doped region, the first epitaxial layer, the first well and the second doped region form the punch-through silicon controlled rectifier, with the first doped region forming the anode and the second doped region forming the cathode of the punch-through silicon controlled rectifier.Type: GrantFiled: September 25, 2020Date of Patent: May 30, 2023Assignee: Alpha & Omega Semiconductor (Cayman) Ltd.Inventor: Shekar Mallikarjunaswamy
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Patent number: 11569345Abstract: A method for manufacturing and a Super Junction MOSFET are disclosed. The Super Junction MOSFET comprises a lightly doped epitaxial layer of a first conductivity type on a heavily doped substrate of the first conductivity type. A deep trench is formed in the epitaxial layer. The deep trench having an insulating layer with a thickness gradient formed on surfaces of the deep trench. One or more regions of the epitaxial layer proximate to sidewalls of the deep trench is doped of a second conductivity type, wherein the second conductivity type is opposite the first conductivity type. Finally, MOSFET device structures are formed in the epitaxial layer.Type: GrantFiled: November 23, 2020Date of Patent: January 31, 2023Assignee: Alpha and Omega Semiconductor (Cayman) Ltd.Inventors: Wenjun Li, Lingbing Chen, Lingpeng Guan, Jian Wang
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Patent number: 11552078Abstract: A method for making an integrated device that includes a plurality of planar MOSFETs, includes forming a plurality of doped body regions in an upper portion of a silicon carbide substrate composition and a plurality of doped source regions. A first contact region is formed in a first source region and a second contact region is formed in a second source region. The first and second contact regions are separated by a JFET region that is longer in one planar dimension than the other. The first and second contact regions are separated by the longer planar dimension. The JFET region is bounded on at least one side corresponding to the longer planar dimension by a source region and a body region in conductive contact with at least one contact region.Type: GrantFiled: September 30, 2020Date of Patent: January 10, 2023Assignee: Alpha and Omega Semiconductor (Cayman) Ltd.Inventor: Vipindas Pala
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Patent number: 11538933Abstract: A trench metal-oxide-semiconductor field-effect transistor (MOSFET) device comprises an active cell area including a plurality of superjunction trench power MOSFETs, and a Schottky diode area including a plurality of Schottky diodes formed in the drift region having the superjunction structure. Each of the integrated Schottky diodes includes a Schottky contact between a lightly doped semiconductor layer and a metallic layer.Type: GrantFiled: September 30, 2020Date of Patent: December 27, 2022Assignee: ALPHA AND OMEGA SEMICONDUCTOR (CAYMAN) LTD.Inventors: Yi Su, Madhur Bobde
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Patent number: 11539293Abstract: A capacitor is discharged to a point where ring back in an output voltage across the capacitor is eliminated in response a transient event to high side and low side switching devices conductively coupled to an inductor and the capacitor before turning on the high side switch and varying an output voltage with a change in a load current.Type: GrantFiled: January 11, 2021Date of Patent: December 27, 2022Assignee: ALPHA AND OMEGA SEMICONDUCTOR (CAYMAN) LTD.Inventor: Amir Babazadeh
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Patent number: 11522451Abstract: An apparatus, comprising, a MOSFET, a controller coupled to the MOSFET, an inductor conductively coupled to the MOSFET. A reported current output of the controller is adjusted based on a predetermined excursion of an attribute of the inductor from a fixed attribute value.Type: GrantFiled: December 13, 2019Date of Patent: December 6, 2022Assignee: ALPHA AND OMEGA SEMICONDUCTOR (CAYMAN) LTD.Inventors: Nicholas I. Archibald, Rhys S. A. Philbrick, Steven P. Laur
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Patent number: 11508819Abstract: A method for forming a superjunction power semiconductor device includes forming multiple epitaxial layers of a first conductivity type on a semiconductor substrate and implanting dopants of a second conductivity type into each epitaxial layer to form a first group of implanted regions in a first region and a second group of implanted regions in a second region in each epitaxial layer. The multiple epitaxial layers are annealed to form multiple columns of the second conductivity type having slanted sidewalls across the first to last epitaxial layers. The columns include a first group of columns formed by the implanted regions of the first group and having a first grading and a second group of columns formed by the implanted regions of the second group and having a second grading, where the second grading is less than the first grading.Type: GrantFiled: May 6, 2021Date of Patent: November 22, 2022Assignee: Alpha and Omega Semiconductor (Cayman) Ltd.Inventors: Madhur Bobde, Karthik Padmanabhan, Lingpeng Guan
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Patent number: 11480987Abstract: An error amplifier circuit receives first and second input signals and provides an error amplifier output signal indicative of the difference between the first and second input signals. The error amplifier circuit implements a proportional-integrator-differentiator (PID) circuit having a differential input signal path and including a proportional amplifier circuit, an integrator amplifier circuit, and a differentiator amplifier circuit. The differentiator amplifier circuit receives an AC coupled input signal. The error amplifier circuit sums the output from the proportional amplifier circuit, the integrator amplifier circuit and the differentiator amplifier circuit to provide the error amplifier output signal where the error amplifier output signal is referenced to a first bias voltage.Type: GrantFiled: July 24, 2021Date of Patent: October 25, 2022Assignee: Alpha and Omega Semiconductor (Cayman) Ltd.Inventors: Steven P. Laur, Rhys Philbrick, Nicholas Archibald
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Patent number: 11462532Abstract: A bidirectional transient voltage suppressor (TVS) circuit for data pins of electronic devices includes two sets of steering diodes and a diode triggered clamp device in some embodiment. In other embodiments, a bidirectional transient voltage suppressor (TVS) circuit for data pins of electronic devices includes two sets of steering diodes with a clamp device merged with a steering diode in each set. The TVS circuit is constructed to realize low capacitance at the protected nodes and improved clamping voltage for robust protection against surge evens. In some embodiments, the TVS circuit realizes low capacitance at the protected nodes by fully or almost completely depleting the P-N junction connected to the protected nodes in the operating voltage range. In this manner, the TVS circuit does not present undesirable parasitic capacitance to the data pins being protected, especially when the data pins are applied in high speed applications.Type: GrantFiled: January 13, 2021Date of Patent: October 4, 2022Assignee: Alpha and Omega Semiconductor (Cayman) Ltd.Inventors: Shekar Mallikarjunaswamy, Ning Shi
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Patent number: 11444000Abstract: A charger includes a thermal conductive plate for heat dissipation, and a transistor. The transistor includes a drain terminal of a first pulsating voltage level, and a source terminal of a second pulsating voltage level. The second pulsating voltage level is lower than the first pulsating voltage level. The source terminal is disposed closer to the thermal conductive plate than the drain terminal.Type: GrantFiled: April 14, 2018Date of Patent: September 13, 2022Assignee: ALPHA AND OMEGA SEMICONDUCTOR (CAYMAN) LTD.Inventors: Yu-Ming Chen, Tien-Chi Lin, Guan-Yu Lin, Tin-Wei Chen
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Patent number: 11342410Abstract: An apparatus comprising an insulated gate bipolar transistor and a super junction metal-oxide semiconductor field effect transistor wherein the insulated gate bipolar transistor and the super-junction metal-oxide semiconductor field effect transistor are electrically and optionally structurally coupled.Type: GrantFiled: September 27, 2019Date of Patent: May 24, 2022Assignee: ALPHA AND OMEGA SEMICONDUCTOR (CAYMAN) LTD.Inventors: Madhur Bobde, Lingpeng Guan, Karthik Padmanabhan, Bum-Seok Suh
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Patent number: 11309233Abstract: A power semiconductor package comprises a lead frame, a low side field-effect transistor (FET), a high side FET, a capacitor, a resistor, an inductor assembly, a first plurality of bonding wires, and a molding encapsulation. In one example, an entirety of the inductor assembly is disposed at a position higher than an entirety of the low side FET, higher than an entirety of the high side FET, and higher than an entirety of the first plurality of bonding wires. In another example, a bottom surface of the low side FET and a bottom surface of the inductor assembly are co-planar.Type: GrantFiled: February 25, 2020Date of Patent: April 19, 2022Assignee: ALPHA AND OMEGA SEMICONDUCTOR (CAYMAN), LTD.Inventors: Xiaotian Zhang, Mary Jane R. Alin, Bo Chen, David Brian Oraboni, Jr., Long-Ching Wang, Jian Yin
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Patent number: 11290021Abstract: A multi-function switch has a Junction-Field Effect Transistor (JFET) that outputs a voltage for both charging and timing/sense the synchronous rectifier controller. Current is provided to a synchronous rectifier controller from a JET having its drain conductively coupled to the drain electrode of the secondary side rectifying MOSFET, wherein the current from the source of the JET is used for both timing/sense and powering the synchronous rectifier controller. The JFET is biased for a fixed output with its source to gate voltage at a turn on threshold voltage of the JFET for charging. The JFET is fully conducting from the secondary side of transformer with a small voltage drop across the drain to source electrode of the secondary side rectifying MOSFET for timing/sense.Type: GrantFiled: January 30, 2020Date of Patent: March 29, 2022Assignee: ALPHA AND OMEGA SEMICONDUCTOR (CAYMAN) LTD.Inventors: Jian Yin, Qihong Huang
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Patent number: 11271559Abstract: A method of generating a gate drive signal for driving a control terminal of a power switch includes detecting a system input signal; determining a signal pulse of the system input signal being a first signal pulse following a power up event, or following an idle period, or following removal of a fault condition; and in response, generating a soft gate drive signal to drive the control terminal of the power switch to softly turn on the power switch. In another embodiment, the method includes determining a duration of the on period of the system input signal exceeding a maximum on duration and in response, disabling the gate drive signal to turn off the power switch; and determining a deassertion transition of the system input signal and in response, blocking the system input signal from the gate drive signal for a minimum off duration.Type: GrantFiled: October 7, 2019Date of Patent: March 8, 2022Assignee: Alpha and Omega Semiconductor (Cayman) Ltd.Inventors: Bum-Seok Suh, Wonjin Cho, Son Tran
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Patent number: 11258270Abstract: A charger comprises a housing, a first multi-layer printed circuit board (PCB), a second multi-layer PCB, and a third multi-layer PCB. The first PCB comprises at least a portion of a primary side circuit. The second PCB comprises at least a portion of a secondary side circuit. The third PCB is perpendicular to the first PCB and the second PCB. An isolation coupling element is disposed on the third PCB. The isolation coupling element comprises a multi-layer PCB. The first PCB comprises a high voltage (HV) semiconductor package. A surface of a die paddle of the HV semiconductor package is exposed from a molding encapsulation of the HV semiconductor package.Type: GrantFiled: June 28, 2019Date of Patent: February 22, 2022Assignee: ALPHA AND OMEGA SEMICONDUCTOR (CAYMAN) LTD.Inventors: Pei-Lun Huang, Yu-Ming Chen, Tien-Chi Lin, Jung-Pei Cheng, Yueh-Ping Yu, Zhi-Qiang Niu, Xiaotian Zhang, Long-Ching Wang
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Patent number: 11245016Abstract: A semiconductor apparatus has a silicon carbide substrate heavily doped with the first conductivity type and a lightly doped silicon carbide drift region of the first conductivity type over the silicon carbide substrate. A first body region in the drift region is doped with second conductivity type opposite the first. A first source region in the first body region is heavily doped with the first conductivity type. A gate trench is formed in the first source region and first body region. At least one sidewall of the gate trench is parallel to a crystal plane of the silicon carbide structure having greater carrier mobility than a C-face thereof. The gate trench extends a length of the first body region and the source region to a separation region laterally adjacent to the first region wherein the separation region is in the drift region.Type: GrantFiled: January 31, 2020Date of Patent: February 8, 2022Assignee: ALPHA AND OMEGA SEMICONDUCTOR (CAYMAN) LTD.Inventors: David Sheridan, Vipindas Pala, Madhur Bobde
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Patent number: 11221658Abstract: A multi-port power delivery system includes a first universal serial bus (USB) port, a second USB port, a first power conversion unit, a second power conversion unit, a power delivery control circuit and a switch circuit. The first USB port is configured to output power delivered to a first power path. The second USB port is configured to output power delivered to a second power path. The first power conversion unit has a first output terminal coupled to the first power path. The second power conversion unit has a second output terminal coupled to the second power path. The power delivery control circuit generates a switch control signal according to first connection information on the first USB port and second connection information on the second USB port. The switch circuit selectively couples the first output terminal to the second output terminal according to the switch control signal.Type: GrantFiled: January 16, 2020Date of Patent: January 11, 2022Assignee: ALPHA AND OMEGA SEMICONDUCTOR (CAYMAN), LTD.Inventors: Pao-Yao Yeh, Yu-Ming Chen, Jung-Pei Cheng, Hsiang-Chung Chang