Patents Assigned to IXYS Corporation
  • Patent number: 9698741
    Abstract: A chopper stabilzed amplifier with synchronous switched capacitor noise filtering is disclosed. In an exemplary embodiment, an apparatus includes a chopper amplifier having an input that receives an input signal and an output that outputs an amplified signal. The chopper amplifier includes an input chopping circuit and an output chopping circuit, where the input and output chopping circuits operate in response to a chop clock. The apparatus also includes a switched capacitor filter having an input that receives the amplified signal and an output that outputs a filtered signal. The switched capacitor filter operates in response to a filter clock. The apparatus also includes a filter timing adjuster that receives a reference voltage and adjusts a phase of the filter clock with respect to the chop clock to reduce chopper noise on that reference voltage.
    Type: Grant
    Filed: September 26, 2016
    Date of Patent: July 4, 2017
    Assignee: IXYS Corporation
    Inventor: Eric Blom
  • Patent number: 9640461
    Abstract: A power module includes a substrate DMB (Direct Metal Bonded). A novel bridging DMB is surface mounted to the substrate DMB along with power semiconductor device dice. The top metal layer of the bridging DMB has one or more islands to which bonding wires can connect. In one example, an electrical path extends from a module terminal, through a first bonding wire and to a first location on a strip-shaped island, through the island to a second location, and from the second location and through a second bonding wire. The strip-shaped island of the bridging DMB serves as a section of the overall electrical path. Another bonding wire of a separate electrical path passes transversely over the strip-shaped island without any wire crossing any other wire. Use of the bridging DMB promotes bonding wire mechanical strength as well as heat sinking from bonding wires down to the substrate DMB.
    Type: Grant
    Filed: July 31, 2016
    Date of Patent: May 2, 2017
    Assignee: IXYS Corporation
    Inventors: Thomas Spann, Ira Balaj-Loos
  • Patent number: 9641065
    Abstract: An AC line filter module includes AC-to-DC rectification circuitry. The rectification circuitry includes four low forward voltage rectifiers coupled together as two high-side rectifiers and two low-side rectifiers, where each low forward voltage rectifier includes an NPN bipolar transistor and a parallel-connected diode. A current splitting pair of inductors splits a return current so that a portion of the current is supplied to the collector of an NPN bipolar transistor that is on, and so that the remainder of the current is supplied to the base of the transistor that is on. Both low-side rectifiers are driven by these current splitting inductors. A pair of base current return diodes provides base current return paths. Due to the use of NPN bipolar transistors and no PNP bipolar transistors, manufacturing cost is reduced and efficiency is improved as compared to an implementation that uses low forward voltage rectifiers having PNP transistors.
    Type: Grant
    Filed: June 6, 2015
    Date of Patent: May 2, 2017
    Assignee: IXYS Corporation
    Inventor: Kyoung Wook Seok
  • Patent number: 9627521
    Abstract: A trench IGBT has a gate electrode disposed in a trench. A tub-shaped floating P-well is disposed on one side of the trench. The tub-shaped floating P-well has a central shallower portion and a peripheral deeper portion. An inner sidewall of the trench is semiconductor material of the peripheral deeper portion of the floating P-well. On the other side of the trench is a P type body region involving a plurality of deeper portions and a plurality of shallower portions. Each deeper portion extends to the trench such that some parts of the outer sidewall of the trench are semiconductor material of these deeper P-body portions. Other parts of the outer sidewall of the trench are semiconductor material of the shallower P-body portions. A shallow N+ emitter region is disposed at the top of the outer sidewall. The IGBT has fast turn off and enhanced on state conductivity modulation.
    Type: Grant
    Filed: July 28, 2016
    Date of Patent: April 18, 2017
    Assignee: IXYS Corporation
    Inventor: Vladimir Tsukanov
  • Patent number: 9601473
    Abstract: A press pack module includes a collector module terminal, an emitter module terminal, a gate module terminal, and an auxiliary module terminal. Each IGBT cassette within the module includes a set of shims, two contact pins, and an IGBT die. The first contact pin provides part of a first electrical connection between the gate module terminal and the IGBT gate pad. The second contact pin provides part of a second electrical connection between the auxiliary module terminal and a shim that in turn contacts the IGBT emitter pad. The electrical connection between the auxiliary emitter terminal and each emitter pad of the many IGBTs is a balanced impedance network. The balanced network is not part of the high current path through the module. By supplying a gate drive signal between the gate and auxiliary emitter terminals, simultaneous IGBT turn off in high speed and high current switching conditions is facilitated.
    Type: Grant
    Filed: October 30, 2015
    Date of Patent: March 21, 2017
    Assignee: IXYS Corporation
    Inventors: Ashley Golland, Franklin J. Wakeman, Howard D. Neal
  • Patent number: 9595950
    Abstract: A High-Voltage Stacked Transistor Circuit (HVSTC) includes a stack of power transistors coupled in series between a first terminal and a second terminal. The HVSTC also has a control terminal for turning on an off the power transistors of the stack. All of the power transistors of the stack turn on together, and turn off together, so that the overall stack operates like a single transistor having a higher breakdown voltage. Each power transistor, other than the one most directly coupled to the first terminal, has an associated bipolar transistor. In a static on state of the HVSTC, the bipolar transistors are off. The associated power transistors can therefore be turned on. In a static off state of the HVSTC, the bipolar transistors are conductive (in one example, in the reverse active mode) in such a way that they keep their associated power transistors off.
    Type: Grant
    Filed: May 31, 2016
    Date of Patent: March 14, 2017
    Assignee: IXYS Corporation
    Inventor: Kyoung Wook Seok
  • Patent number: 9590092
    Abstract: A Super Junction Field Effect Transistor (FET) device includes a charge compensation region disposed on a substrate of semiconductor material. The charge compensation region includes a set of strip-shaped P? type columns, a floating ring-shaped P? type column that surrounds the set of strip-shaped P? type columns, and a set of ring-shaped P? type columns that surrounds the floating ring-shaped P? type column. A source metal is disposed above portions of the charge compensation region. The source metal contacts each of the strip-shaped P? type columns and each of the ring-shaped P? type columns. An oxide is disposed between the floating P? type column and the source metal such that the floating P? type column is electrically isolated from the source metal. The device exhibits a breakdown voltage that is 0.2% greater than if the floating P? type column were to contact the source metal.
    Type: Grant
    Filed: November 13, 2014
    Date of Patent: March 7, 2017
    Assignee: IXYS Corporation
    Inventor: Kyoung Wook Seok
  • Patent number: 9590033
    Abstract: A manufacturable and economically viable edge termination structure allows a semiconductor device to withstand a very high reverse blocking voltage (for example, 8500 volts) without suffering breakdown. A P type peripheral aluminum diffusion region extends around the bottom periphery of a thick die. The peripheral aluminum diffusion region extends upward from the bottom surface of the die, extending into N? type bulk silicon. A deep peripheral trench extends around the upper periphery of the die. The deep trench extends from the topside of the die down toward the peripheral aluminum diffusion region. A P type sidewall doped region extends laterally inward from the inner sidewall of the trench, and extends laterally outward from the outer sidewall of the trench. The P type sidewall doped region joins with the P type peripheral aluminum diffusion region, thereby forming a separation edge diffusion structure that surrounds the active area of the die.
    Type: Grant
    Filed: November 20, 2015
    Date of Patent: March 7, 2017
    Assignee: IXYS Corporation
    Inventors: Elmar Wisotzki, Christoph Koerber
  • Patent number: 9589953
    Abstract: A Reverse Bipolar Junction Transistor (RBJT) integrated circuit comprises a bipolar transistor and a parallel-connected distributed diode, where the base region is connected neither to the collector electrode nor to the emitter electrode. The bipolar transistor has unusually high emitter-to-base and emitter-to-collector reverse breakdown voltages. In the case of a PNP-type RBJT, an N base region extends into a P? epitaxial layer, and a plurality of P++ collector regions extend into the base region. Each collector region is annular, and rings a corresponding diode cathode region. Parts of the epitaxial layer serve as the emitter, and other parts serve as the diode anode. Insulation features separate metal of the collector electrode from the base region, and from P? type silicon of the epitaxial layer, so that the diode cathode is separated from the base region. This separation prevents base current leakage and reduces power dissipation during steady state on operation.
    Type: Grant
    Filed: March 31, 2015
    Date of Patent: March 7, 2017
    Assignee: IXYS Corporation
    Inventor: Kyoung Wook Seok
  • Patent number: 9571003
    Abstract: Within a non-isolated and efficient AC-to-DC power supply circuit: 1) a dep-FET is turned off to decouple an output voltage VO node from a VR node when a rectifier output signal VR on the VR node is greater than a first predetermined voltage VP and, 2) the dep-FET is enabled to be turned on so that a constant charging current flows from the VR node and onto the VO node when VR is less than VP (provided that VO is less than a second predetermined voltage VO(MAX) and provided that VR is adequately greater than VO). To speed turn off and on of the dep-FET, gate charge of the dep-FET is removed and is stored in a second capacitor when the dep-FET is to be turned off, and charge from the second capacitor is moved back onto the gate of the dep-FET when the dep-FET is to be turned on.
    Type: Grant
    Filed: April 30, 2015
    Date of Patent: February 14, 2017
    Assignee: IXYS Corporation
    Inventor: Leonid A. Neyman
  • Patent number: 9544961
    Abstract: A system for driving a multi-stage LED with low distortion and with current proportional to rectified input voltage is disclosed. In an exemplary embodiment, an apparatus includes LED groups connected in series to form an LED string having a first node, a last node, and intermediate nodes. The apparatus also includes current cells having inputs coupled to the nodes and outputs coupled to an output resistor. Each current cell selectively regulates current to flow between its respective input and the output resistor. The apparatus also includes a feedback circuit that generates a plurality of feedback voltages from a voltage level at the output resistor. When a selected current cell is enabled by a selected feedback voltage to regulate a selected current level from its respective input to the output resistor, upstream current cells are disabled by their respective feedback voltages.
    Type: Grant
    Filed: December 22, 2015
    Date of Patent: January 10, 2017
    Assignee: IXYS Corporation
    Inventors: Bret Ross Howe, Narasimham Patibandla
  • Patent number: 9473074
    Abstract: A chopper stabilized amplifier with synchronous switched capacitor noise filtering is disclosed. In an exemplary embodiment, an apparatus includes a chopper amplifier having an input that receives an input signal and an output that outputs an amplified signal. The chopper amplifier includes an input chopping circuit and an output chopping circuit, where the input and output chopping circuits operate in response to a chop clock. The apparatus also includes a switched capacitor filter having an input that receives the amplified signal and an output that outputs a filtered signal. The switched capacitor filter operates in response to a filter clock. The apparatus also includes a filter timing adjuster that receives a reference voltage and adjusts a phase of the filter clock with respect to the chop clock to reduce chopper noise on that reference voltage.
    Type: Grant
    Filed: September 14, 2015
    Date of Patent: October 18, 2016
    Assignee: IXYS Corporation
    Inventor: Eric Blom
  • Patent number: 9443792
    Abstract: A power module includes a substrate DMB (Direct Metal Bonded). A novel bridging DMB is surface mounted to the substrate DMB along with power semiconductor device dice. The top metal layer of the bridging DMB has one or more islands to which bonding wires can connect. In one example, an electrical path extends from a module terminal, through a first bonding wire and to a first location on a strip-shaped island, through the island to a second location, and from the second location and through a second bonding wire. The strip-shaped island of the bridging DMB serves as a section of the overall electrical path. Another bonding wire of a separate electrical path passes transversely over the strip-shaped island without any wire crossing any other wire. Use of the bridging DMB promotes bonding wire mechanical strength as well as heat sinking from bonding wires down to the substrate DMB.
    Type: Grant
    Filed: October 31, 2015
    Date of Patent: September 13, 2016
    Assignee: IXYS Corporation
    Inventors: Thomas Spann, Ira Balaj-Loos
  • Patent number: 9419118
    Abstract: A trench IGBT has a gate electrode disposed in a trench. A tub-shaped floating P-well is disposed on one side of the trench. The tub-shaped floating P-well has a central shallower portion and a peripheral deeper portion. An inner sidewall of the trench is semiconductor material of the peripheral deeper portion of the floating P-well. On the other side of the trench is a P type body region involving a plurality of deeper portions and a plurality of shallower portions. Each deeper portion extends to the trench such that some parts of the outer sidewall of the trench are semiconductor material of these deeper P-body portions. Other parts of the outer sidewall of the trench are semiconductor material of the shallower P-body portions. A shallow N+ emitter region is disposed at the top of the outer sidewall. The IGBT has fast turn off and enhanced on state conductivity modulation.
    Type: Grant
    Filed: November 3, 2015
    Date of Patent: August 16, 2016
    Assignee: IXYS Corporation
    Inventor: Vladimir Tsukanov
  • Patent number: 9379203
    Abstract: An ultra-fast breakover diode has a turn on time TON that is less than 0.3 microseconds, where the forward breakover voltage is greater than +400 volts and varies less than one percent per ten degrees Celsius change. In another aspect of the invention, a breakover diode has a reverse breakdown voltage that is greater, in absolute magnitude, than the forward breakover voltage, where the forward breakover voltage is greater than +400 volts. Yet another aspect of the invention involves a string of series-connected breakover diode dice, along with a resistor string, in a packaged circuit. The packaged circuit acts like a single breakover diode having a large forward breakover voltage and a comparably large reverse breakdown voltage, even though the packaged circuit includes no discrete high voltage reverse breakdown diode. The packaged circuit is usable to supply a triggering current to a thyristor in a voltage protection circuit.
    Type: Grant
    Filed: June 6, 2015
    Date of Patent: June 28, 2016
    Assignee: IXYS Corporation
    Inventor: Subhas Chandra Bose Jayappa Veeramma
  • Patent number: 9355580
    Abstract: A display device includes a display panel; and a backlight panel provided below the display panel and defining a plurality of regions. A first array of light emitting diodes (LEDs) is provided along a first direction, each LED of the first array being coupled to a first line. A driver is coupled to the first line to drive the LEDs coupled to the first line. A second array of LEDs is provided along a second direction, each LEDs of the second array being coupled to a second line. A lighting condition of the regions defined by the backlight panel is controlled by turning on or off the LEDs.
    Type: Grant
    Filed: June 19, 2013
    Date of Patent: May 31, 2016
    Assignee: IXYS Corporation
    Inventors: Nathan Zommer, Sam Seiichiro Ochi
  • Patent number: 9350254
    Abstract: A Low Forward Voltage Rectifier (LFVR) includes a bipolar transistor, a parallel diode, and a base current injection circuit disposed in an easy-to-employ two-terminal package. In one example, the transistor is a Reverse Bipolar Junction Transistor (RBJT), the diode is a distributed diode, and the base current injection circuit is a current transformer. Under forward bias conditions (when the voltage from the first package terminal to the second package terminal is positive), the LFVR conducts current at a rated current level with a low forward voltage drop (for example, approximately 0.1 volts). In reverse bias conditions, the LFVR blocks current flow. Using the LFVR in place of a conventional silicon diode rectifier in the secondary of a flyback converter reduces average power dissipation and increases power supply efficiency.
    Type: Grant
    Filed: July 2, 2015
    Date of Patent: May 24, 2016
    Assignee: IXYS Corporation
    Inventor: Kyoung Wook Seok
  • Patent number: 9337744
    Abstract: An AC-to-DC converter involves a rectifier, an inductor, a storage capacitor, a switch, and a microcontroller. In a capacitor pre-charge operation, the periodicity and voltage amplitude of an AC supply voltage are determined. Based on this, the microcontroller identifies one of a plurality of stored sequences. Each sequence is a list of values. The microcontroller turns off the switch on AC supply voltage zero crossings and turns on the switch in accordance with the values. As a result, a sequence of identical pulses of charging current flows into the storage capacitor. Each pulse passes in a current path from the rectifier, through the inductor, through the capacitor, through the switch, and back to the rectifier. During the pre-charge operation, the microcontroller does not measure the capacitor voltage and use that to calculate when to the turn the switch on next, but rather the sequence of precalculated stored values is used.
    Type: Grant
    Filed: April 30, 2015
    Date of Patent: May 10, 2016
    Assignee: IXYS Corporation
    Inventor: Anatoliy V. Tsyrganovich
  • Patent number: 9337616
    Abstract: Embodiments for driving a laser diode includes generating a bias current having a duty cycle that is less than 100%. The current level of the bias current is insufficient to turn on the laser diode. A drive current is generated and combined with the bias current to turn on the laser diode almost instantly.
    Type: Grant
    Filed: June 30, 2014
    Date of Patent: May 10, 2016
    Assignee: IXYS Corporation
    Inventor: James Budai
  • Patent number: 9337171
    Abstract: A full bridge rectifier includes four bipolar transistors, each of which has an associated parallel diode. A first pair of inductors provides inductive current splitting and thereby provides base current to/from one pair of the bipolar transistors so that the collector-to-emitter voltages of the bipolar transistors are low. A second pair of inductors similarly provides inductive current splitting to provide base current to/from the other pair of bipolar transistors. In one embodiment, all components are provided in a four terminal full bridge rectifier module. The module can be used as a drop-in replacement for a conventional four terminal full bridge diode rectifier. When current flows through the rectifier module, however, the voltage drop across the module is less than one volt. Due to the reduced low voltage drop, power loss in the rectifier module is reduced as compared to power loss in a conventional full bridge diode rectifier.
    Type: Grant
    Filed: March 27, 2015
    Date of Patent: May 10, 2016
    Assignee: IXYS Corporation
    Inventor: Kyoung Wook Seok