Patents Assigned to Alpha & Omega Semiconductor, Ltd.
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Publication number: 20120293144Abstract: A voltage/current control apparatus and method are disclosed. The apparatus includes a low-side field effect transistor (FET) having a source, a gate and a drain, a high-side field effect transistor (FET) having a source, a gate and a drain, a gate driver integrated circuit (IC), a sample and hold circuit, and a comparator configured to produce a trigger signal at the output when a sum of the first and second input signals is equal to a sum of the third and fourth input signals, wherein the trigger signal is configured to trigger a beginning of a new cycle by turning the gate of the high-side FET “on” and the gate of the low-side FET “off”.Type: ApplicationFiled: May 17, 2011Publication date: November 22, 2012Applicant: ALPHA & OMEGA SEMICONDUCTOR, LTD.Inventor: Yu Cheng Chang
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Patent number: 8120887Abstract: An electronic device formed as an integrated circuit (IC) wherein the electronic device further includes a transient voltage suppressing (TVS) circuit. The TVS circuit includes a triggering MOS transistor connected between an emitter and a collector of a first bipolar-junction transistor (BJT) coupled to a second BJT to form a SCR functioning as a main clamp circuit of the TVS circuit. The TVS circuit further includes a triggering circuit for generating a triggering signal for the triggering MOS transistor wherein the triggering circuit includes multiple stacked MOS transistors for turning into a conductive state by a transient voltage while maintaining a low leakage current.Type: GrantFiled: February 28, 2007Date of Patent: February 21, 2012Assignee: Alpha & Omega Semiconductor, Ltd.Inventors: Shekar Mallikararjunaswamy, Madhur Bobde
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Patent number: 8120142Abstract: An electronic circuit includes a filtering circuit implemented with a distributed inductor-and-capacitor (LC) network that includes metal oxide effect (MOS) trenches opened in a semiconductor substrate filled with dielectric material for functioning as capacitors for the distributed LC network. The electronic circuit further includes a transient voltage suppressing (TVS) circuit integrated with the filtering circuit that functions as a low pass filter wherein the TVS circuit includes a bipolar transistor triggered by a diode disposed in the semiconductor substrate. The distributed LC network further includes metal coils to function as inductors disposed on a top surface of the semiconductor electrically contacting the MOS trenches.Type: GrantFiled: April 18, 2008Date of Patent: February 21, 2012Assignee: Alpha & Omega Semiconductor, Ltd.Inventor: Madhur Bobde
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Patent number: 8105905Abstract: A novel integration scheme for forming power MOSFET, particularly forming salicides for both gate and mesa contact regions, as well as using multiple energy contact implants through the salicided layer to form conductive body contacts which short to the source region by the salicides.Type: GrantFiled: November 8, 2010Date of Patent: January 31, 2012Assignee: Alpha & Omega Semiconductor, Ltd.Inventors: Yongzhong Hu, Sung-Shan Tai
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Publication number: 20120001176Abstract: A semiconductor device wafer includes a test structure. The test structure includes a layer of material having an angle-shaped test portion disposed on at least a portion of a surface of the semiconductor wafer. A ruler marking on the surface of the semiconductor wafer proximate the test portion is adapted to facilitate measurement of a change in length of the test portion.Type: ApplicationFiled: September 13, 2011Publication date: January 5, 2012Applicant: ALPHA & OMEGA SEMICONDUCTOR, LTD.Inventors: Yingying Lou, Tiesheng Li, Yu Wang, Anup Bhalla
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Patent number: 8089139Abstract: A TSOP (Thin Small Outline Package) contains a MOSFET and a Schottky diode. The MOSFET has a source terminal a gate terminal and a drain terminal. The Schottky diode has a cathode terminal, a anode terminal. The TSOP contains the MOSFET and the Schottky diode with a special configuration by placing the drain terminal of the MOSFET and the anode terminal of the Schottky diode on a same side. Specifically, the TSOP implements a leadframe that comprises a plurality of leads. The drain terminal of the MOSFET and the anode terminal extends outside of the TSOP separate on the same side of the package.Type: GrantFiled: October 9, 2005Date of Patent: January 3, 2012Assignee: Alpha & Omega Semiconductor, Ltd.Inventors: Zhengyu Shi, Limin Wang, Lei Shi
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Publication number: 20110316090Abstract: A boost converter for high power and high output voltage applications includes a low voltage controller integrated circuit and a high voltage, vertical, discrete field effect transistor, both of which are packed in a single package on separate electrically isolated die pads.Type: ApplicationFiled: September 1, 2011Publication date: December 29, 2011Applicant: ALPHA & OMEGA SEMICONDUCTOR, LTD.Inventors: ALLEN CHANG, Wai-Keung Peter Cheng
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Patent number: 8058687Abstract: This invention discloses a trenched metal oxide semiconductor field effect transistor (MOSFET) cell. The trenched MOSFET cell includes a trenched gate opened from a top surface of the semiconductor substrate surrounded by a source region encompassed in a body region above a drain region disposed on a bottom surface of a substrate. The trenched gate further includes at least two mutually insulated trench-filling segments each filled with materials of different work functions. In an exemplary embodiment, the trenched gate includes a polysilicon segment at a bottom portion of the trenched gate and a metal segment at a top portion of the trenched gate.Type: GrantFiled: January 30, 2007Date of Patent: November 15, 2011Assignee: Alpha & Omega Semiconductor, Ltd.Inventors: Sung-Shan Tai, YongZhong Hu
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Patent number: 8053808Abstract: A semiconductor power device supported on a semiconductor substrate includes a plurality of transistor cells each having a source and a drain with a gate to control an electric current transmitted between the source and the drain. The semiconductor further includes a source metal connected to the source region, and a gate metal configured as a metal stripe surrounding a peripheral region of the substrate connected to a gate pad wherein the gate metal and the gate pad are separated from the source metal by a metal gap. The semiconductor power device further includes an ESD protection circuit includes a plurality of doped polysilicon regions of opposite conductivity types constituting ESD diodes extending across the metal gap and connected between the gate metal and the source metal on the peripheral region of the substrate.Type: GrantFiled: May 21, 2007Date of Patent: November 8, 2011Assignee: Alpha & Omega Semiconductor, Ltd.Inventors: Yi Su, Anup Bhalla, Daniel Ng, Wei Wang, Ji Pan
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Patent number: 8035159Abstract: This invention discloses a semiconductor power device. The trenched semiconductor power device includes a trenched gate, opened from a top surface of a semiconductor substrate, surrounded by a source region encompassed in a body region near the top surface above a drain region disposed on a bottom surface of a substrate. The semiconductor power device further includes an implanting-ion block disposed above the top surface on a mesa area next to the body region having a thickness substantially larger than 0.3 micron for blocking body implanting ions and source ions from entering into the substrate under the mesa area whereby masks for manufacturing the semiconductor power device can be reduced.Type: GrantFiled: April 30, 2007Date of Patent: October 11, 2011Assignee: Alpha & Omega Semiconductor, Ltd.Inventors: Anup Bhalla, François Hébert, Sung-Shan Tai, Sik K Lui
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Publication number: 20110227155Abstract: A main FET and one or more sense FETs are formed in a common substrate. The main FET and sense FET(s) include a source terminal, a gate terminal and a drain terminal. The common gate pad connects the gate terminals of the main FET and sense FET(s). An electrical isolation may be between the gate terminals of the main FET and the sense FET(s). A sense pad in electrical contact with the source of the one or more sense FETs does not overlap an area of the device containing the sense FET(s). It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.Type: ApplicationFiled: May 31, 2011Publication date: September 22, 2011Applicant: ALPHA & OMEGA SEMICONDUCTOR, LTD.Inventors: Yi Su, Anup Bhalla, Daniel Ng
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Patent number: 8008747Abstract: This invention discloses a semiconductor power device disposed on a semiconductor substrate supporting an epitaxial layer as a drift region composed of an epitaxial layer. The semiconductor power device further includes a super-junction structure includes a plurality of doped sidewall columns disposed in a multiple of epitaxial layers. The epitaxial layer have a plurality of trenches opened and filled with the multiple epitaxial layer therein with the doped columns disposed along sidewalls of the trenches disposed in the multiple of epitaxial layers.Type: GrantFiled: February 28, 2008Date of Patent: August 30, 2011Assignee: Alpha & Omega Semiconductor, Ltd.Inventors: François Hébert, Anup Bhalla
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Patent number: 7933102Abstract: This invention discloses an electronic device formed as an integrated circuit (IC) wherein the electronic device further includes a transient voltage suppressing (TVS) circuit. The TVS circuit includes a triggering Zener diode connected between an emitter and a collector of a bipolar-junction transistor (BJT) wherein the Zener diode having a reverse breakdown voltage BV less than or equal to a BVceo of the BJT where BVceo stands for a collector to emitter breakdown voltage with base left open. The TVS circuit further includes a rectifier connected in parallel to the BJT for triggering a rectified current through the rectifier for further limiting an increase of a reverse blocking voltage.Type: GrantFiled: May 15, 2009Date of Patent: April 26, 2011Assignee: Alpha & Omega Semiconductor, Ltd.Inventor: Shekar Mallikararjunaswamy
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Patent number: 7880223Abstract: A method for manufacturing a transient voltage suppressing (TVS) array substantially following a manufacturing process for manufacturing a vertical semiconductor power device. The method includes a step of opening a plurality of isolation trenches in an epitaxial layer of a first conductivity type in a semiconductor substrate followed by applying a body mask for doping a body region having a second conductivity type between two of the isolation trenches. The method further includes a step of applying an source mask for implanting a plurality of doped regions of the first conductivity type constituting a plurality of diodes wherein the isolation trenches isolating and preventing parasitic PNP or NPN transistor due to a latch-up between the doped regions of different conductivity types.Type: GrantFiled: November 30, 2006Date of Patent: February 1, 2011Assignee: Alpha & Omega Semiconductor, Ltd.Inventor: Madhur Bobde
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Patent number: 7863675Abstract: This invention discloses a new MOSFET device. The MOSFET device has an improved operation characteristic achieved by manufacturing a MOSFET with a higher gate work function by implementing a P-doped gate in an N-MOSFET device. The P-type gate increases the threshold voltage and shifts the C-Vds characteristics. The reduced Cgd thus achieves the purpose of suppressing the shoot through and resolve the difficulties discussed above. Unlike the conventional techniques, the reduction of the capacitance Cgd is achieved without requiring complicated fabrication processes and control of the recess electrode.Type: GrantFiled: March 22, 2008Date of Patent: January 4, 2011Assignee: Alpha & Omega Semiconductor, Ltd.Inventors: Anup Bhalla, Sik K. Lui
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Patent number: 7855422Abstract: A semiconductor device includes a transistor, a capacitor and a resistor wherein the capacitor includes a doped polysilicon layer to function as a bottom conductive layer with a salicide block (SAB) layer as a dielectric layer covered by a Ti/TiN layer as a top conductive layer thus constituting a single polysilicon layer metal-insulator-polysilicon (MIP) structure. While the high sheet rho resistor is also formed on the same single polysilicon layer with differential doping of the polysilicon layer.Type: GrantFiled: May 31, 2006Date of Patent: December 21, 2010Assignee: Alpha & Omega Semiconductor, Ltd.Inventors: YongZhong Hu, Sung-Shan Tai
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Patent number: 7838977Abstract: This invention discloses an electronic package for containing a vertical semiconductor chip that includes a laminated board having a via connector and conductive traces distributed on multiple layers of the laminated board connected to the via connector. The semiconductor chip having at least one electrode connected to the conductive traces for electrically connected to the conductive traces at a different layer on the laminated board and the via connector dissipating heat generated from the vertical semiconductor. A ball grid array (BGA) connected to the via connector functioning as contact at a bottom surface of the package for mounting on electrical terminals disposed on a printed circuit board (PCB) wherein the laminated board having a thermal expansion coefficient in substantially a same range the PCB whereby the BGA having a reliable electrical contact with the electrical terminals.Type: GrantFiled: September 7, 2005Date of Patent: November 23, 2010Assignee: Alpha & Omega Semiconductor, Ltd.Inventors: Ming Sun, Yueh Se Ho
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Patent number: 7829989Abstract: An electronic package for containing at least a top packaging module vertically stacked on a bottom packaging module. Each of the packaging modules includes a semiconductor chip packaged and connected by via connectors and connectors disposed on a laminated board fabricated with a standard printed-circuit board process wherein the top and bottom packaging module further configured as a surface mountable modules for conveniently stacking and mounting to prearranged electrical contacts without using a leadframe. At least one of the top and bottom packaging modules is a multi-chip module (MCM) containing at least two semiconductor chips. At least one of the top and bottom packaging modules includes a ball grid array (BGA) for surface mounting onto the prearranged electrical contacts. At least one of the top and bottom packaging modules includes a plurality of solder bumps on one of the semiconductor chips for surface mounting onto the prearranged electrical contacts.Type: GrantFiled: December 22, 2005Date of Patent: November 9, 2010Assignee: Alpha & Omega Semiconductor, Ltd.Inventors: Ming Sun, Yueh Se Ho
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Patent number: 7829941Abstract: A novel integration scheme for forming power MOSFET, particularly forming salicides for both gate and mesa contact regions, as well as using multiple energy contact implants through the salicided layer to form conductive body contacts which short to the source region by the salicides.Type: GrantFiled: January 24, 2006Date of Patent: November 9, 2010Assignee: Alpha & Omega Semiconductor, Ltd.Inventors: Yongzhong Hu, Sung-Shan Tai
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Patent number: 7824977Abstract: A semiconductor wafer includes at least a partially manufactured high voltage transistor covered by a high-voltage low voltage decoupling layer and at least a partially manufactured low voltage transistor with the high-voltage low-voltage decoupling layer etched off for further performance of a low-voltage manufacturing process thereon. The high-voltage low-voltage decoupling layer comprising a high temperature oxide (HTO) oxide layer of about 30-150 Angstroms and a low-pressure chemical vapor deposition (LPCVD) nitride layer.Type: GrantFiled: March 27, 2007Date of Patent: November 2, 2010Assignee: Alpha & Omega Semiconductor, Ltd.Inventors: YongZhong Hu, Sung-Shan Tai