IXYS Patent Applications

BUCK CONVERTER HAVING SELF-DRIVEN BJT SYNCHRONOUS RECTIFIER

Granted: June 4, 2015
Application Number: 20150155785
A switching converter has a self-driven bipolar junction transistor (BJT) synchronous rectifier. The BJT rectifier includes a BJT and a parallel-connected diode, and has a low forward voltage drop. In a first portion of a switching cycle, a main switch is on and the BJT rectifier is off. Current flows from an input, through the main switch, through the first inductor, to an output. Current also flows through the main switch, through the second inductor, to the output. In a second portion…

FORWARD CONVERTER WITH SELF-DRIVEN BJT SYNCHRONOUS RECTIFIER

Granted: May 21, 2015
Application Number: 20150138839
An AC-to-DC converter circuit includes DC-to-DC converter that in turn includes a secondary side circuit. The secondary side circuit includes a secondary winding, a pair of bipolar transistor-based self-driven synchronous rectifiers, a pair of current splitting inductors, and an output capacitor. Each of the synchronous rectifiers includes a bipolar transistor and a diode whose anode is coupled to the transistor collector and whose cathode is coupled to the transistor emitter. The…

POWER DEVICE CASSETTE WITH AUXILIARY EMITTER CONTACT

Granted: April 16, 2015
Application Number: 20150102383
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…

SINTERED BACKSIDE SHIM IN A PRESS PACK CASSETTE

Granted: April 16, 2015
Application Number: 20150102481
Within a cassette of a press pack module, a conductive shim is bonded to the backside of a device die by a layer of sintered metal. The die, sintered metal, and shim together form a sintered assembly. The cassette is compressed between a metal top plate member and a metal bottom plate member such that the backside of the assembly is pressed against the top plate member, and such that the frontside of the assembly is pressed against another shim. A central portion of the frontside surface…

HIGH VOLTAGE BREAKOVER DIODE HAVING COMPARABLE FORWARD BREAKOVER AND REVERSE BREAKDOWN VOLTAGES

Granted: November 13, 2014
Application Number: 20140332841
In a first embodiment, 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 a second embodiment, 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. In a third embodiment, a string of…

PACKAGED OVERVOLTAGE PROTECTION CIRCUIT FOR TRIGGERING THYRISTORS

Granted: November 13, 2014
Application Number: 20140332842
In a first embodiment, 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 a second embodiment, 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. In a third embodiment, a string of…

Vertical Power MOSFET And IGBT Fabrication Process With Two Fewer Photomasks

Granted: September 18, 2014
Application Number: 20140273357
A process for fabrication of a power semiconductor device is disclosed in which a single photomask is used to define each of p-conductivity well regions and n-conductivity type source regions. In the process a single photomask is deposited on a layer of polysilicon on a wafer, the polysilicon layer is removed from first regions of the power semiconductor device where the p-conductivity well regions and the n-conductivity type source regions are to be formed, and both p-conductivity type…

POWER TRANSISTOR WITH INCREASED AVALANCHE CURRENT AND ENERGY RATING

Granted: September 18, 2014
Application Number: 20140273384
A field-effect transistor involves a drain electrode, a drift region, a body region, a source region, a gate insulator layer, and a gate electrode. The drift region is disposed above the drain electrode. The body region extends down into the drift region from a first upper semiconductor surface. The source region is ladder-shaped and extends down in the body region from a second upper semiconductor surface. The first and second upper semiconductor surfaces are substantially planar and…

Module and Assembly with Dual DC-Links for Three-Level NPC Applications

Granted: September 11, 2014
Application Number: 20140252410
A power semiconductor module has four power terminals. An IGBT has a collector connected to the first power terminal and an emitter coupled to the third power terminal. An anti-parallel diode is coupled in parallel with the IGBT. A DC-link is connected between the second and fourth power terminals. The DC-link may involve two diodes and two IGBTs, where the IGBTs are connected in a common collector configuration. The first and second power terminals are disposed in a first line along one…

FAST RECOVERY SWITCHING DIODE WITH CARRIER STORAGE AREA

Granted: September 4, 2014
Application Number: 20140246761
A power device (such as a power diode) has a peripheral die area and a central area. The main PN junction of the device is formed by a P+ type region that extends down into an N? type layer. The central portion of the P+ type region has a plurality of openings so mesa structures of the underlying N? type material extend up to the semiconductor surface through the openings. Due to the mesa structures being located in the central portion of the die, there are vertically extending…

Solderless Die Attach to a Direct Bonded Aluminum Substrate

Granted: August 14, 2014
Application Number: 20140225267
A DBA-based power device includes a DBA (Direct Bonded Aluminum) substrate. An amount of silver nanoparticle paste of a desired shape and size is deposited (for example by micro-jet deposition) onto a metal plate of the DBA. The paste is then sintered, thereby forming a sintered silver feature that is in electrical contact with an aluminum plate of the DBA. The DBA is bonded (for example, is ultrasonically welded) to a lead of a leadframe. Silver is deposited onto the wafer back side and…

Blank Bit and Processor Instructions Employing the Blank Bit

Granted: August 7, 2014
Application Number: 20140223146
Reading a value into a register, checking to see if the value is a NULL, and then jumping out of a loop if the value is a NULL is a common task that processors perform. To speed performance of such a task, a novel “blank bit” is added to the flag register of a processor. When a first instruction (arithmetic, logic or load) is executed, the instruction operands are checked to see if any is a NULL character value. Information on the result of the check is stored in the blank bit.…

SILVER-TO-SILVER BONDED IC PACKAGE HAVING TWO CERAMIC SUBSTRATES EXPOSED ON THE OUTSIDE OF THE PACKAGE

Granted: July 3, 2014
Application Number: 20140183716
A packaged power device involves no soft solder and no wire bonds. The direct-bonded metal layers of two direct metal bonded ceramic substrate assemblies, such as Direct Bonded Aluminum (DBA) substrates, are provided with sintered silver pads. Silver nanoparticle paste is applied to pads on the frontside of a die and the paste is sintered to form silver pads. Silver formed by an evaporative process covers the backside of the die. The die is pressed between the two DBAs such that direct…

NON-ISOLATED AC-TO-DC CONVERTER HAVING A LOW CHARGING CURRENT INITIAL POWER UP MODE

Granted: May 8, 2014
Application Number: 20140126258
In a steady state operation mode, a charging circuit of a non-isolated AC-to-DC converter decouples an output voltage VO node from a VR node when the rectifier output signal VR on the VR node is greater than a first predetermined voltage VP and, 2) supplies a charging current from the VR node and onto the VO node when VR is less than VP provided that an output voltage VO on the VO node is less than a second predetermined voltage VO(MAX) and provided that VR is greater than VO. In an…

IGBT DIE STRUCTURE WITH AUXILIARY P WELL TERMINAL

Granted: May 1, 2014
Application Number: 20140118055
An IGBT die structure includes an auxiliary P well region. A terminal, that is not connected to any other IGBT terminal, is coupled to the auxiliary P well region. To accelerate IGBT turn on, a current is injected into the terminal during the turn on time. The injected current causes charge carriers to be injected into the N drift layer of the IGBT, thereby reducing turn on time. To accelerate IGBT turn off, charge carriers are removed from the N drift layer by drawing current out of the…

LOW FORWARD VOLTAGE RECTIFIER

Granted: May 1, 2014
Application Number: 20140119064
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…

Recovering Energy From An IrDA/Remote Control Transmitter Circuit

Granted: February 20, 2014
Application Number: 20140049183
A portable electronic device with an IrDA transmitter LED is used to transmit both IrDA signals and remote control infrared signals. The device transmits remote control infrared signals with reduced power consumption. During a relatively longer remote control signal pulse, an inductor saturates and stores energy when a drive current flows from a power supply, through the inductor and then through the LED. An energy-transferring circuit transfers a portion of the energy stored in the…

Power MOSFET Having Selectively Silvered Pads for Clip and Bond Wire Attach

Granted: February 13, 2014
Application Number: 20140042624
A packaged power field effect transistor device includes a power field effect transistor die, a DBA substrate, a clip, a wire bond, leads, and an amount of plastic encapsulant. The top of the DBA has a plurality of metal plate islands. A sintered silver feature is disposed on one of the islands. A silvered backside of the die is directly bonded to the sintered silver structure of the DBA. The upper surface of the die includes a first aluminum pad (a source pad) and a second aluminum pad…

High-Efficiency, Low-Power Power Supply Circuit

Granted: February 13, 2014
Application Number: 20140043878
A power supply circuit includes a rectifier, a charging circuit, and a storage capacitor. An AC signal is rectified by the rectifier thereby generating a rectified signal VR between a VR node and a GND node. The capacitor is coupled between an output voltage VO node and the GND node. If VR is greater than a first predetermined voltage VP then the VO node is decoupled from the VR node. If VR is below VP then the charging circuit supplies a substantially constant charging current from the…

Solderless Die Attach to a Direct Bonded Aluminum Substrate

Granted: December 12, 2013
Application Number: 20130328204
A DBA-based power device includes a DBA (Direct Bonded Aluminum) substrate. An amount of silver nanoparticle paste of a desired shape and size is deposited (for example by micro-jet deposition) onto a metal plate of the DBA. The paste is then sintered, thereby forming a sintered silver feature that is in electrical contact with an aluminum plate of the DBA. The DBA is bonded (for example, is ultrasonically welded) to a lead of a leadframe. Silver is deposited onto the wafer back side and…