1710 results about "Zener diode" patented technology

The invention comprises use of Dynamically Switchable Bypass (DSB) elements in association with one or more Light Emitting Diodes (LEDs) in arrays for illumination circuits to provide rugged, reliable lighting. The DSBs are selected from Transient Voltage Suppressors, including Silicon, Metal Oxide Varistors, and Multi Layer Varistors as well as Zener Diodes. The DSBs are not used as circuit protecting devices, but rather as alternative paths for electric current to bypass failed LEDs. Bi-directional TVSs are used as alternative electric paths for circuits using Alternating Current (AC) and parallel LED arrays that light on both phases of AC. Zener Diodes are used in parallel to, but in the opposite polarity orientation to, one or more LEDs in DC or rectified AC circuits. The inventive paired DSB/LED elements overcomes the black-out problems of prior series LED illumination systems, making possible the use of robust LEDs in illumination systems where reliability, long life, low power consumption, low heat output, resistance to shock, vibration, and humidity, and self-diagnosis are important. The DSB elements have breakdown voltages slightly higher than the LED(s) they support, so that when an LED fails, the conduction through the DSB begins. Because the conduction voltage of the DSB so nearly matches the conduction voltage of the LED(s), the remainder of the circuit continues to function as normal. The system is self-diagnostic in that any LED failure presents itself as a dark LED rather than as a whole string of dark LEDs. DSBs may be used with incandescent bulbs.

LED driver circuits containing voltage reducing devices, voltage regulating devices, and voltage converting devices are disclosed as the main components to provide power to LEDs. The LED driver circuits are designed to work with a ballast, mains alternating current voltage, direct current voltage, and electromagnetic induction power. The voltage regulating devices can be a resistor in series with at least one zener diode or a voltage regulator both in parallel with and providing power to the LEDs. The LEDs can also be anti-parallel diode pairs consisting of one diode and one LED or two LEDs, or the LEDs can be anti-parallel diode string pairs consisting of diodes and LEDs or all LEDs. The LED driver circuits will be incorporated into LED replacement lamps, and in particular to LED lamps to replace fluorescent lamps for use with existing ballasts and other power sources where the ballast may be removed or bypassed.

The AC output from a source is rectified and applied to a resistor/Zener diode circuit connection which determines the magnitude of the rectified voltage applied via a circuit to a first MOSFET device. The inverted output of the first MOSFET device is applied to the gate electrode of a second MOSFET device in a manner such that the second MOSFET device is ON even when the AC output passes through zero. The output of the second MOSFET device is connected to a resistor which determines the magnitude of the load applied to the dimmer.

A transient-voltage suppressing (TVS) device disposed on a semiconductor substrate including a low-side steering diode, a high-side steering diode integrated with a main Zener diode for suppressing a transient voltage. The low-side steering diode and the high-side steering diode integrated with the Zener diode are disposed in the semiconductor substrate and each constituting a vertical PN junction as vertical diodes in the semiconductor substrate whereby reducing a lateral area occupied by the TVS device. In an exemplary embodiment, the high-side steering diode and the Zener diode are vertically overlapped with each other for further reducing lateral areas occupied by the TVS device.

Integrated circuit antifuse circuitry is provided. A metal-oxide-semiconductor (MOS) antifuse transistor serves as an electrically-programmable antifuse. In its unprogrammed state, the antifuse transistor is off and has a relatively high resistance. During programming, the antifuse transistor is turned on which melts the underlying silicon and causes a permanent reduction in the transistor's resistance. A sensing circuit monitors the resistance of the antifuse transistor and supplies a high or low output signal accordingly. The antifuse transistor may be turned on during programming by raising the voltage at its substrate relative to its source. The substrate may be connected to ground through a resistor. The substrate may be biased by causing current to flow through the resistor. Current may be made to flow through the resistor by inducing avalanche breakdown of the drain-substrate junction or by producing Zener breakdown of external Zener diode circuitry connected to the resistor.

An electrical circuit for providing electrical power for use in powering electronic devices, such as monitors, televisions, white goods, data centers, and telecom circuit boards, is described herein. The electrical circuit includes a voltage reduction circuit and a rectifier circuit for delivering input power signal to the voltage reduction circuit. The voltage reduction circuit is configured to receive an input power signal and generate an output power signal at a lower voltage level. The rectifier circuit includes a full wave bridge rectifier coupled to the electrical power source, a Zener based charging circuit coupled to the full wave bridge rectifier, a voltage divider coupled to the Zener based charging circuit and the full wave bridge rectifier, and an output terminal coupled to the full wave bridge rectifier, the Zener based charging circuit, and the voltage divider for delivering the input power signal to the voltage reduction circuit.

A transient voltage/surge current protection system is provided for electronic circuits associated with implanted leads. In particular, a transient voltage suppressor such as a diode, a zener diode, a transorb, a surge protector, varistor components or the like, is placed in parallel with the electronic circuits to thereby divert harmful surge current and bypass the electronic circuit during an external defibrillation event or during an applied therapeutic shock, such as from an ICD.

An electrostatic discharge (ESD) protection clamp (61) for I/O terminals (22, 23) of integrated circuits (ICs) (24) comprises an NPN bipolar transistor (25) coupled to an integrated Zener diode (30). Variations in the break-down current-voltage characteristics (311, 312, 313, 314) of multiple prior art ESD clamps (31) in different parts of the same IC chip is avoided by forming the anode (301) of the Zener (30) in the shape of a base-coupled P+ annular ring (75) surrounded by a spaced-apart N+ annular collector ring (70) for the cathode (302) of the Zener (30). Even though an angled implant (51, 86, 98) used to form the N+ annular collector ring (70) causes location dependent variations in the width (53) of the Zener space charge (ZSC) region (69), the improved annular shaped clamp (61) always has a portion that initiates break-down at the design voltage so that variations in the width (53) of the ZSC region (69) do not cause significant variations in the clamp's current-voltage characteristics (611, 612, 613, 614).

The present invention relates to an electronic ballast that energizes fluorescent lamps connected in a parallel configuration. The ballast employs a power factor correcting boost converter that can be used over a wide range of AC line voltages to provide regulated power to a self-oscillating sine wave inverter that drives the fluorescent lighting load at high frequencies. The inverter employs special networks that limit a certain type of shoot-through current, and thus improve the efficiency of the unit. Also included is a restart circuit that limits power losses during the zero lamp condition, by periodically interrupting the inverter operation when the zero lamp state is detected. To improve operation of the power factor correcting circuitry over the wide range of AC line voltages, a DC offset is added to the sampled AC voltage at the higher AC line voltages by Zener diode based coupling circuit.

A thermal management system for reducing or eliminating heat-mediated degradation of LED performance and/or operating life. The system may include a thermal controller arranged to respond to an LED operating condition, and to responsively limit temperature in the LED. The thermal controller in one implementation includes a bypass circuit containing a bypass control element, such as a varistor, Zener diode, or antifuse device, and arranged to divert current from flowing to the LED so that the LED remains in a cool state, e.g., below 75° C. The system may be arranged to (I) at least partially attenuate the power supplied to an LED so as to reduce heat generation in such LED and maintain the LED below a threshold temperature and/or (II) remove heat from the LED to maintain temperature of the LED below a threshold temperature.

A transient-voltage suppressing (TVS) device disposed on a semiconductor substrate of a first conductivity type. The TVS includes a buried dopant region of a second conductivity type disposed and encompassed in an epitaxial layer of the first conductivity type wherein the buried dopant region extends laterally and has an extended bottom junction area interfacing with the underlying portion of the epitaxial layer thus constituting a Zener diode for the TVS device. The TVS device further includes a region above the buried dopant region further comprising a top dopant layer of a second conductivity type and a top contact region of a second conductivity type which act in combination with the epitaxial layer and the buried dopant region to form a plurality of interfacing PN junctions constituting a SCR acting as a steering diode to function with the Zener diode for suppressing a transient voltage.

There is presented a light emitting device, having plural light emitting elements disposed on a substrate, in which a protection element, such as a zener diode, can be disposed at an appropriate position. The light emitting device includes: a substrate; a light emitting section having plural light emitting elements disposed in a mounting area on the substrate; a positive electrode and negative electrode each having a pad section and wiring section to apply voltage to the light emitting section through the wiring sections; a protection element disposed at one of the positive electrode and negative electrode and electrically connected with the other one electrode; and a light reflecting resin formed on the substrate such as to cover at least the wiring sections and the protection element, wherein the wiring sections are formed along the periphery of the mounting area such that one end portions thereof are adjacent to each other.

Accompanying the miniaturization of a gate electrode of a trench gate power MOSFET, the curvature of the bottom part of the trench increases, and thereby, electric fields concentrate on the part and deterioration of a gate oxide film (insulating film) occurs. The deterioration of the gate insulating film is more likely to occur when the gate side bias is negative in the case of an N-channel type power MOSFET and when the gate side bias is positive in the case of a P-channel type power MOSFET.

The present invention is a semiconductor device including an insulating gate power transistor etc. in a chip, wherein a gate protection element includes a bidirectional Zener diode and the bidirectional Zener diode has a plurality of P-type impurity regions (or a P-type impurity region) having different concentrations so that the withstand voltage with its gate side negatively biased and the withstand voltage with the gate side positively biased are different from each other.

In an LED lamp, a Zener diode is mounted on a copper plate, and a GaN-based light-emitting element is mounted on the Zener diode with an electrode of the element being oriented facedown. Two Zener diodes close to the center of the LED lamp are mounted on a common copper plate, thereby interconnecting the two light-emitting elements in series. Consequently, a Zener diode is connected to the respective two Zener diodes by means of a wire serving as a conductive member. Four light-emitting elements are connected in series, so that four light-emitting elements are connected in series, thus completing a circuit configuration. In this way, use of the Zener diodes for interconnection purpose enables a reduction in the number of minimum required wires. It is better to connect the wire to the upper surfaces of the Zener diodes, thereby obviating a necessity for a redundant wire space and enabling miniaturization of the LED lamp.

A composite field effect transistor, in accordance with one embodiment, includes a zener diode, a junction field effect transistor and a metal-oxide-semiconductor field effect transistor. A gate of the junction field effect transistor is coupled to an anode of the zener diode. A cathode of the zener diode is coupled to a gate of the metal-oxide-semiconductor field effect transistor. A drain of the metal-oxide-semiconductor field effect transistor is coupled to a source of the junction field effect transistor.

A semiconductor laser apparatus has a Zener diode containing a first semiconductor region of a first conduction type and a second semiconductor region of a second conduction type joined with the first semiconductor region, and a vertical-cavity surface-emitting semiconductor laser diode stacked above the Zener diode and containing at least a first mirror layer of a first conduction type, a second mirror layer of a second conduction type and an active region sandwiched between the first and second mirror layers. The first semiconductor region and the second mirror layer are electrically connected and the second semiconductor region and the first mirror layer are electrically connected.

An LED includes a light-generating semiconductor region having an active layer sandwiched between two confining layers of opposite conductivity types for generating light. A cathode is arranged centrally on one of the opposite major surfaces of the semiconductor region from which is emitted the light. A reflector of electroconductive material is formed on the other major surface of the semiconductor region for reflecting the light back toward the light-emitting surface of the semiconductor region. For protecting the LED against breakdown from overvoltages, a zener diode is employed which takes the form of a baseplate having two semiconductor regions of opposite conductivity types sandwiched between a pair of electrodes in the form of metal layers. The protector baseplate is integrated with the light-generating semiconductor region by joining one of the metal layers to the reflector under heat and pressure, thus serving as both mechanical support and overvoltage protector for the LED.

A power supply arrangement including a transformer and a switching element coupled to a primary winding of the transformer and a power supply. The power supply includes a capacitor having a first terminal coupled to a junction of the primary winding and the switching element and a first diode coupled between the capacitor and an output node. The power supply further includes a discharge element, such as a resistor or a diode, coupled between the junction of the first diode and the capacitor and a power supply common. A voltage regulator, such as a Zener diode, is connected to the output node to produce a regulated voltage powered by the voltage applied to the transformer primary winding, with the regulated voltage being used to power the control circuitry.

A light-adjusting and current-limiting control circuit for a lamp includes a sampling circuit formed of a manganese-copper line or a current transformer, a power circuit provided with resistors, capacitors, diodes, a Varistor and a zener diode, a signal adjusting circuit composed of diodes, resistors, a varistor, triacs and capacitors, and a control output circuit having a thyristor, diodes, a relay and an LED. The control output circuit can be replaced with a light-adjusting input circuit, a chip processor control circuit, a zero-crossing detection circuit and a two-way silicon controlled rectifier control output circuit 5. Thus, the invention has a low cost, a small size and an excellent precision, compared to conventional ones.

A MOSFET device that includes a first Zener diode connected between a gate metal and a drain metal of said semiconductor power device for functioning as a gate-drain (GD) clamp diode. The GD clamp diode includes multiple back-to-back doped regions in a polysilicon layer doped with dopant ions of a first conductivity type next to a second conductivity type disposed on an insulation layer above the MOSFET device, having an avalanche voltage lower than a source/drain avalanche voltage of the MOSFET device wherein the Zener diode is insulated from a doped region of the MOSFET device for preventing a channeling effect. The MOSFET device further includes a second Zener diode connected between a gate metal and a source metal of the MOSFET device for functioning as a gate-source (GS) clamp diode, wherein the GD clamp diode includes multiple back-to-back doped regions in the polysilicon layer doped with dopant ions of a first conductivity type next to a second conductivity type disposed on the insulation layer above the MOSFET device having a lower breakdown voltage than a gate oxide rupture voltage of the MOSFET device.