Abstract: A cellular telephone case has front and back panels. A cellular telephone is coupled to the case by pushing the telephone into the case such that the main dock connector of the telephone engages a plug on the back panel. When the telephone is in this position, a back surface of the telephone is held in place on an inside surface of the back panel. The front panel is hinged so that it folds over and covers the telephone. In this folded position, the upward and outward facing outside surface of the front panel includes an E-ink display, a plurality of photovoltaic cells for charging a rechargeable battery of the case, and several buttons. Image information from the telephone is transferred to the case through the dock connector, and then viewed on the display using energy stored in the battery, even after the telephone has been decoupled from the case.

Abstract: 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 current splitting inductors provide the necessary base current to the bipolar transistors at the appropriate times such that the bipolar transistors operate as synchronous rectifiers.

Abstract: 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 VR node, through the charging circuit, to the VO node, and to the capacitor, provided that VO on the capacitor is below a second predetermined voltage VO(MAX) and provided that VR is adequately high with respect to VO. Due to the charging current, the voltage VO on the storage capacitor is restored to the desired second predetermined voltage.

Abstract: 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 of the cycle, the main switch is turned off but the inductor currents continue to flow. Current flows from a ground node, through the BJT rectifier, through the first inductor, to the output. The BJT is on due to the second inductor drawing a base current from the BJT. In one example, the main switch is a split-source NFET that conducts separate currents through the two inductors.

Abstract: A packaged power semiconductor device is provided with voltage isolation between a metal backside and terminals of the device. The packaged power semiconductor device is arranged in an encapsulant defining a hole for receiving a structure for physically coupling the device to an object. A direct-bonded copper (“DBC”) substrate is used to provide electrical isolation and improved thermal transfer from the device to a heatsink. At least one power semiconductor die is mounted to a first metal layer of the DBC substrate. The first metal layer spreads heat generated by the semiconductor die. In one embodiment, the packaged power semiconductor device conforms to a TO-247 outline and is capable of receiving a screw for physically coupling the device to a heatsink.

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.

Abstract: 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 side of the module, and the third and fourth power terminals are disposed in a second line along the opposite side of the module. Two identical instances of the module can be interconnected together to form a three-level NPC phase leg having low stray inductances, where the phase leg has two parallel DC-links.

Abstract: 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 the wafer is singulated into dice. In a solderless silver-to-silver die attach process, the silvered back side of a die is pressed down onto the sintered silver feature on the top side of the DBA. At an appropriate temperature and pressure, the silver of the die fuses to the sintered silver of the DBA. After wirebonding, encapsulation and lead trimming, the DBA-based power device is completed.

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.

Abstract: 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 of the die is contacted on the bottom by the other shim, but there is no shim contacting a peripheral portion of the frontside surface. Despite there being no shim in contact with the peripheral portion of the frontside surface, the peripheral portion is in good thermal contact with the top plate member through the sintered metal and the bonded conductive shim.

Abstract: A system for communicating with a host using control signals over a 1-wire interface is disclosed. The system includes a driver coupled to the host by the 1-wire interface. Control signals are transmitted from the host to the driver for decoding by the driver controller. The control signals are pulse width modulation format signals which are interpreted by the driver as binary encoded command mode signals or analog encoded command mode signals, depending upon when the signals are received in relation to a preamble pulse and a post-amble pulse.

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.

Abstract: A split-body Super Junction FET is made using only seven masks. Thin oxide is disposed on an upper semiconductor surface of a super junction charge compensation region. A polysilicon gate is disposed on the thin oxide. An ILD (InterLayer Dielectric) layer is disposed on the upper surface of the thin oxide so that the ILD layer covers the polysilicon gate. A gate bus line metal structure and a field plate metal structure are disposed on the upper surface of the ILD. A portion of the upper surface of the ILD extends from the gate bus line metal, laterally over floating rings, and to the field plate metal. This portion of the upper surface of the ILD layer is substantially planar where the ILD layer passes over the floating rings. The field plate metal structure, a polysilicon feature, and a diffusion region together form a stepped depletion layer field plate structure.

Abstract: 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 silver-to-silver bonds are formed between sintered silver pads on the frontside of the die and corresponding sintered silver pads of one of the DBAs, and such that a direct silver-to-silver bond is formed between the backside silver of the die and a sintered silver pad of the other DBA. After leadforming, leadtrimming and encapsulation, the finished device has exposed ceramic of both DBAs on outside package surfaces.

Abstract: 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 initial power up operation mode, the maximum limit value of the charging current is smaller than it is during steady state operation. Due to the reduced charging currents employed during initial power up operation, less noise is injected back to the AC source and EMI filters are not required between the rectifier of the converter and the AC source.

Abstract: 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 of the cycle, the main switch is turned off but the inductor currents continue to flow. Current flows from a ground node, through the BJT rectifier, through the first inductor, to the output. The BJT is on due to the second inductor drawing a base current from the BJT. In one example, the main switch is a split-source NFET that conducts separate currents through the two inductors.

Abstract: A Low Forward Voltage Rectifier (LFVR) circuit includes a bipolar transistor, a parallel diode, and a capacitive current splitting network. The LFVR circuit, when it is performing a rectifying function, conducts the forward current from a first node to a second node provided that the voltage from the first node to the second node is adequately positive. The capacitive current splitting network causes a portion of the forward current to be a base current of the bipolar transistor, thereby biasing the transistor so that the forward current experiences a low forward voltage drop across the transistor. The LFVR circuit sees use in as a rectifier in many different types of switching power converters, including in flyback, Cuk, SEPIC, boost, buck-boost, PFC, half-bridge resonant, and full-bridge resonant converters. Due to the low forward voltage drop across the LFVR, converter efficiency is improved.

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.

Abstract: 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 current splitting inductors provide the necessary base current to the bipolar transistors at the appropriate times such that the bipolar transistors operate as synchronous rectifiers.

Abstract: A portable electronic device includes a housing including an outer surface and an inner surface. A core electronic component is configured to be provided inside of the housing. A transparent material is provided at the outer surface of the housing. A solar cell is provided on the inner surface of the housing and spaced apart from the transparent material by a predetermined distance. The transparent material is configured to receive light from an external source and direct the light to the solar cell.