IXYS Patent Grants

AC line filter and AC-to-DC rectifier module

Granted: April 17, 2018
Patent Number: 9948205
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…

Inverse diode stack

Granted: April 10, 2018
Patent Number: 9941256
A packaged inverse diode device exhibits superior commutation robustness. The device includes a stack of inverse diodes disposed within a housing. Each adjacent pair of inverse diodes is bonded together by an intervening DMB (Direct Metal Bonded) substrate structure. At one end of the stack of diode dice and DMB substrate structures is attached a first metal terminal. A second metal terminal is attached to the other end of the stack. The two terminals serve as package terminals of the…

Packaged overvoltage protection circuit for triggering thyristors

Granted: April 3, 2018
Patent Number: 9935206
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…

Power semiconductor device module baseplate having peripheral heels

Granted: March 27, 2018
Patent Number: 9929066
The baseplate of a power semiconductor device module makes reliable and superior thermal contact with a heatsink when fixed to the heatsink. The baseplate includes a rectangular plate portion, a first downward-extending peripheral heel extension portion, and a second downward-extending peripheral heel extension portion. In one example, the plate portion has four mounting holes for receiving mounting bolts. There is one mounting hole located adjacent each of four corners of the…

Multi-stage LED driver with current proportional to rectified input voltage and low distortion

Granted: March 20, 2018
Patent Number: 9924573
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…

AC line filter and AC-to-DC rectifier module

Granted: March 20, 2018
Patent Number: 9923324
An AC Line Filter/Rectifier Module (ACLF/RM) has a metal housing and an outward appearance of a conventional AC line filter, but the ACLF/RM includes circuitry that performs both EMI filtering and line filtering as well as very efficient AC-to-DC rectification. Rectification circuitry within the ACLF/RM rectifies an AC voltage signal received onto AC input module terminals and outputs a rectified version of the AC voltage signal onto DC output module terminals. The rectification…

Trench separation diffusion for high voltage device

Granted: March 20, 2018
Patent Number: 9922864
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…

Gate driver that drives with a sequence of gate resistances

Granted: March 6, 2018
Patent Number: 9912331
A gate driver integrated circuit for driving a gate of an IGBT or MOSFET receives an input signal. In response to a rising edge of the input signal, the integrated circuit causes the gate to be driven in a first sequence of time periods. In each period, the gate is driven high (pulled up) via a corresponding one of a plurality of different effective gate resistances. In response to a falling edge of the input signal, the integrated circuit causes the gate to be driven in a second…

IGBT die structure with auxiliary P well terminal

Granted: March 6, 2018
Patent Number: 9911838
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…

Programmable temperature compensated voltage generator

Granted: January 2, 2018
Patent Number: 9857823
A programmable temperature compensated voltage reference is disclosed. In an exemplary embodiment, an apparatus includes a digital-to-analog converter (DAC) that uses a reference voltage and a code to generate a DAC output voltage. The apparatus also includes a temperature compensator that uses a temperature measurement (T) and the DAC code to generate a temperature compensation signal. The temperature compensation signal is represented by a third order polynomial equation. The apparatus…

Lead and lead frame for power package

Granted: December 12, 2017
Patent Number: 9842795
A power device includes a semiconductor chip provided over a substrate, and a patterned lead. The patterned lead includes a raised portion located between a main portion and an end portion. At least part of the raised portion is positioned over the semiconductor chip at a larger height than both the main portion and the end portion. A bonding pad may also be included. The end portion may include a raised portion, bonded portion, and connecting portion. At least part of the bonded portion…

Power MOSFET having improved manufacturability, low on-resistance and high breakdown voltage

Granted: December 5, 2017
Patent Number: 9837529
Stripe-shaped surface transistor structures of a power MOSFET are disposed over an array of parallel-extending P type Buried Stripe-Shaped Charge Compensation Regions (BSSCCRs). The power MOSFET has two and only two epitaxial semiconductor layers, and the BSSCCRs are disposed at the interface between these layers. Looping around the area occupied by these parallel-extending BSSCCRs is a P type ring-shaped BSSCCR. At the upper semiconductor surface are disposed three P type surface rings.…

Gate driver that drives with a sequence of gate resistances

Granted: November 7, 2017
Patent Number: 9813055
A gate driver integrated circuit for driving a gate of an IGBT or MOSFET receives an input signal. In response to a rising edge of the input signal, the integrated circuit causes the gate to be driven in a first sequence of time periods. In each period, the gate is driven high (pulled up) via a corresponding one of a plurality of different effective gate resistances. In response to a falling edge of the input signal, the integrated circuit causes the gate to be driven in a second…

Buck converter having self-driven BJT synchronous rectifier

Granted: October 24, 2017
Patent Number: 9800159
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…

IGBT assembly having saturable inductor for soft landing a diode recovery current

Granted: October 17, 2017
Patent Number: 9793352
A combination switch includes an Insulated Gate Bipolar Transistor (IGBT), an anti-parallel diode, and a saturable inductor. The diode and inductor are coupled in series between a collector and an emitter of the IGBT. The inductor is fashioned so that it will come out of saturation when a forward bias current flow through the diode falls below a saturation current level. When the diode current falls (for example, due to another combination switch of a phase leg turning on), the diode…

Method of joining metal-ceramic substrates to metal bodies

Granted: October 17, 2017
Patent Number: 9790130
A method of joining a metal-ceramic substrate having metallization on at least one side to a metal body by using metal alloy is disclosed. The metal body has a thickness of less than 1.0 mm and the metal alloy contains aluminum and has a liquidus temperature of greater than 450° C. The resulting metal-ceramic module provides a strong bond between the metal body and the ceramic substrate. The resulting module is useful as a circuit carrier in electronic appliances, with the metal body…

Synchronous sensing of inductor current in a buck converter control circuit

Granted: October 3, 2017
Patent Number: 9780648
A sense resistor is placed in series with an output capacitor of a buck converter. The buck converter operates in a discontinuous mode such that there is a dead time in each switching cycle. A control circuit senses a voltage across the sense resistor and thereby generates a first signal ICS. The control circuit detects an offset voltage in ICS, where the offset voltage is the voltage of ICS during the dead time in a first switching cycle. The control circuit level shifts the entire ICS…

Trench IGBT with waved floating P-well electron injection

Granted: October 3, 2017
Patent Number: 9780202
A trench IGBT includes a floating P well and a floating N+ well that extends down into the floating P well. A bottom surface of the floating P well has a novel waved contour so that it has thinner portions and thicker portions. When the IGBT is on, electrons flow from an N+ emitter, vertically through a channel along a trench sidewall, and to an N? type drift layer. Additional electrons flow through the channel but then pass under the trench, through the floating P well to the floating…

IGBT with waved floating P-well electron injection

Granted: October 3, 2017
Patent Number: 9780168
An IGBT includes a floating P well, and a floating N+ well that extends down into the floating P well. A bottom surface of the floating P well has a waved contour so that it has thinner portions and thicker portions. When the device is on, electrons flow laterally from an N+ emitter, and through a first channel region. Some electrons pass downward, but others pass laterally through the floating N+ well to a local bipolar transistor located at a thinner portion of the floating P type…

Low forward voltage rectifier

Granted: July 11, 2017
Patent Number: 9705417
A rectifier includes a larger Field Effect Transistor (FET1) and a smaller FET (FET2). A sense resistor is in series with FET2's body diode between a cathode terminal and an anode terminal. If the cathode terminal voltage is greater than the voltage on the anode terminal, then body diodes of FETs are reverse biased, the FETs are controlled to be off, and there is no current flow through the rectifier. If, however, the voltage on the anode terminal becomes positive with respect to the…