Abstract: The present invention relates to a band-gap reference circuit. The circuit comprises a plurality of diodes connected in series in one or more chains, a current source to flow current through the diode chains, and a selection of shunt current sources. The shunt current sources are connected in parallel with the main current sources and each, or any, can be selected in order to add current to the diode chain. In this manner, current flow through the diode chain is adjusted in order to provide a trimmable band-gap reference voltage. By adjusting the current flow, the high precision reference voltage circuit can provide a very accurate reference value for variations in process state, process error and temperature.

Abstract: A voltage transformer for AC/DC comprising an IC having a rectifying unit with a function to transform AC of full waveform to continuous semi waveform, and a wave-filtering unit employing Gate transient voltage preset by Field Effect Transistor to proceed with filtering sample by ON and OFF method such that the preset voltage passes through the output terminal and achieves the effect of transformed voltage, and a voltage stabilizing unit which processes the output voltage for suitable utilization, wherein the sampling method of the AC with respect to Field Effect Transistor includes: (i) Fixed voltage sampling and (ii) Fixed time sampling method.

Abstract: To provide a stabilized current to a current modulator or the like in a limited voltage headroom environment, the a current mirror having first and second mirror transistors is provided. Bases of the transistors are coupled together through a resistive element, with base leakage current to the first transistor generating a voltage drop across the resistive element. The voltage drop acts to boost a voltage through an emitter resistor of an output stage of the current mirror, the output stage realized by at least the second mirror transistor. With boosting of the voltage through the emitter resistor there is a corresponding boost in output current defined by the voltage across emitter resistor. As such, the circuit effectively increases the operating voltage and hence the voltage headroom derived from a supply voltage provided to the bases of the first and second mirror transistors.

Abstract: The invention concerns a voltage-current converter having: a first current mirror containing two transistors that are designed such that under identical drive conditions the current flowing through the first transistor is greater than the current flowing through the second transistor by a predetermined factor. The current through the second transistor constitutes the output current of the voltage-current converter. The very large area required in integrated circuits for known voltage-current converters is reduced by providing a second current mirror containing two transistors. The two current mirrors are connected in series to a supply voltage. A MOSFET is connected in series with the first transistor of the first current mirror. The gate of the MOSFET is connected to the input voltage.

Abstract: The invention relates to a semiconductor circuit having a drive circuit, a load that is disposed between a supply voltage, and a controllable, clocked semiconductor switching element for clocked switching of the load. The invention furthermore relates to a switch-mode power supply having such a semiconductor circuit.

Abstract: A non-linear temperature compensation circuit (10) is provided for generating at least dual-slope characteristics responsive to changes in operating temperature of the compensation circuit. The compensation circuit includes a temperature dependent current generator circuit (11) for generating at least one output (I4) substantially proportional to changes in the temperature of the circuit, a current-based dual-slope drift generator (12) for generating a current proportional to absolute temperature, and a summing means (14) for summing both current outputs and generating a compensation drift voltage. The temperature dependent current generator includes a sub-circuit having a first current generator that generates a current (I2) that is relatively independent of temperature, and a second current generator that generates a second current (I3) that decreases with increases in temperature.

Abstract: A high voltage regulation circuit, in which an output voltage is regulated by the resistance distribution method using a differential amplifier during a normal state but by having a current flow through both ends of the resistors of a high voltage regulator when a noise is inputted thereto. The present invention includes a high voltage regulation part regulating a high voltage by having a constant current flow through both ends of resistors of a high voltage regulator when a noise is inputted thereto, a high voltage level detection part controlling a high voltage regulation operation by detecting that an output voltage is reduced to a level equal to or lower than a predetermined level, and a current mirror part providing the high voltage regulation part with a constant current by being equipped with a current source.

Abstract: A harmonic mitigating apparatus connected between a three phase power source and a load provides a multiple-winding reactor for reducing harmonics directed from the load to the source, the apparatus including, for each system phase, first and second line windings in series between the source and load and oriented so as to have the same polarity such that the winding fluxes add thereby increasing total reactance to harmonics directed from the load to the supply, the apparatus also including at least one trap circuit including a series inductance and capacitor for each phase and linked between the first and second line windings and a neutral point (or another phase), the trap circuit characterized by a reactance that is lower than the reactance of the first line winding such that harmonics flow into the trap circuit, for each phase, at least two of the first and second line windings and the trap winding arranged on the same core.

Abstract: A transformer has a primary winding connected between a pair of d.c. input terminals via an on-off switch, and a secondary winding connected between a pair of d.c. output terminals via a rectifying and smoothing circuit. The output voltage applied from the rectifying and smoothing circuit to the load is held constant by switching the input voltage through feedback control. For intermittently operating the switch under light load, a sawtooth generator circuit is provided which provides a sawtooth voltage having a frequency less than that of the on-off operation of the switch. The sawtooth voltage is compared with a voltage indicative of the magnitude of a current flowing through the switch. The result of this comparison is utilized for modifying the delivery of switching pulses to the switch.

Abstract: Presented is a single-stage power converter topology allowing for power factor correction during operation. The topology utilizes an integration of Ćuk converter and single-ended primary inductance converter (SEPIC) topologies to provide AC-to-AC, AC-to-DC, DC-to-AC, and AC/DC-to-AC operation. Shared use of the Ćuk converter's output inductor by the SEPIC-type circuit elements provides continuous output current, typically unknown to a SEPIC converter. Application of the single-stage power converter topologies may be had in a line conditioner circuit, a battery charger circuit, and as an uninterruptible power supply (UPS).

Abstract: A DC power supply device comprises an AC/DC converter 1, a DC/DC converter 2, and a DC converter 3 converting DC power from a battery 4 to DC voltage for connecting to output terminals of the AC/DC converter. The DC power supply device is provided with a controlling circuit 100 which observes a charging control level and a load sharing level, impresses a charging command on a UPS controlling part controlling the DC converter, and simultaneously provides a PFC controlling part controlling the AC/DC converter with a current command when a voltage level is less than the charging control level, stops only the charging command when the voltage level is more than the charging level and less than the load sharing level, and provides the UPS controlling part and the PFC controlling part with current commands when the voltage level is more than the load sharing level.

Abstract: A switched mode power supply having a regulated reflected voltage. In one embodiment, a switched mode power supply includes a power supply regulator coupled between a positive input supply rail of the power supply and a primary winding of an energy transfer element. The reflected voltage across the primary winding of the transfer element is related to the output voltage across a secondary winding of the energy transfer element according to the turns ratio of the energy transfer element. The power supply regulator is coupled to regulate the reflected voltage across the primary winding, thereby regulating the output voltage across secondary winding. In one embodiment, the reflected voltage across the primary winding is sensed through a current representative of the reflected voltage received by the power supply regulator.

Abstract: The voltage converter circuit has first and second input terminals, and first and second output nodes, and comprises: a first power switch connected between the first input terminal and the first output node; a second power switch connected between the first output node and the second input terminal; a first delay circuit having first and second terminals connected between the first input terminal and a control terminal of the first power switch; and a second delay circuit having first and second terminals connected between the first output terminal and a control terminal of the second power switch. Each delay circuit detects a variation in the voltage supplied on the respective first terminal and detects an operating condition of the respective power switch on the second terminal, and supplies to the control terminal of the respective power switch a switching on delay signal.

Abstract: Power factor correction apparatus, for a switching power supply fed by an array of rectifying diodes and consisting of at least an input inductor, a contact of which is connected in series with a contact of the array, and of a power switch connected between the other contact of the array and the other contact of the input inductor that comprises circuitry for identifying, in each cycle determined by the switching frequency of the power supply, whenever the instantaneous value of the current through the inductor reaches a minimal value; circuitry for switching the power switch to its conducting state in response to the minimal current through the inductor; circuitry for reflecting the current flowing through the inductor by a measurable or simulated parameter; and circuitry for providing indication, in each cycle, by using the parameter, the indication being related to the timing until the peak value of the current, that corresponds to a specific load, has been essentially reached, or to the time from the mome

Abstract: An RC series circuit is provided in parallel with an inductor. The RC series circuit is comprised of a resistor and a capacitor which are connected with each other in series. A voltage across the capacitor is applied to a detection circuit. The detection circuit detects inductor current flowing through the inductor based on the applied voltage. If the inductance of the inductor, the parasitic resistance value of the inductor, the capacitance of the capacitor and the resistance value of the resistor are L, RL, Ca and Ra, respectively, the RC series circuit is designed so as to satisfy L/RL=Ca*Ra.

Abstract: A tapped inductor buck converter which achieves zero voltage switching and continuous input and output terminal currents is revealed. To achieve these results an additional switch, a small inductor, and a capacitor are required. The small inductor serves as a source of energy for driving the critical turn on transition of the main switch and the same small inductor also serves as a filter component for smoothing the input and output terminal currents. Simple adaptive gate drive circuits are revealed that improve the timing for turn on of zero voltage switches and reduce gate drive losses. A synchronous rectifier self drive mechanism is revealed which is universally applicable to zero voltage switching power converters with a single main switch which rely on an auxiliary inductor to drive the critical turn on transition of the single main switch. The wave form generated by the auxiliary inductor is ideally suited to synchronous rectifier self drive.

Abstract: A power inverter includes a multi-level switching circuit for switching between any two voltage levels selected from a set of N voltage levels. The switching circuit includes at least N+1 switching elements. Each switching element has a corresponding resonant capacitor connected parallel to it. As the switching elements turn on and off, different ones of the resonant capacitors cooperate with a resonant inductor connected to a pole of the switching circuit and with an output capacitor in maintaining a resonance condition as seen from the active switching elements.

Abstract: A voltage regulator illustrating one embodiment of the apparatus of the present invention is described. The voltage regulator includes an output stage for providing an output voltage on an output voltage terminal, a first switch for charging the output stage, and a second switch for discharging output stage 201. The voltage regulator also includes an input signal terminal for receiving a control signal and a third switch for preventing the second switch from closing when the control signal is asserted. When the control signal on the input signal terminal is not asserted, the voltage regulator operates as a typical switching regulator, alternately charging and discharging the output stage to maintain a stable output voltage on the output voltage terminal. A portion of the power supplied to charge the output stage is consumed every time the output stage is discharged.

Abstract: A switching mode voltage regulator circuit that operates at reduced quiescent current levels is provided. The voltage regulator preferably includes a control circuit and a switching element that connects and disconnects filter circuitry from the control circuit. An error amplifier in the control circuit is placed in a micropower operating state when the regulator is in standby mode to reduce quiescent current.

Abstract: The subject matter disclosed herein relates to mechanisms for programming power supply circuitry for providing an appropriate current or voltage to powering portable devices or recharge batteries. More particularly, a power supply is coupled to a portable device of battery through a connector which is associated with the portable device or battery. The connecter includes resistive circuitry which is detectable at the power supply for programming the power supply to provide the appropriate voltage or current associated with the portable device or battery.