Abstract: An integrated gate drive controller for a synchronous rectifier circuit which minimizes secondary side stray inductance effects in the synchronous transistor branches by controlling overlap of the gate drive signals to the synchronous transistors.

Abstract: A self-oscillating circuit for driving high-side and low-side switching devices, such as MOSFETs connected in a half-bridge configuration. The circuit alternately turns on the switching devices by providing alternating gate pulses varying in duration or width. The pulses are separated by dead time to prevent cross conduction. At start up, the pulses increase from a minimum duration of zero to a maximum duration, while dead time duration simultaneously decreases to its minimum duration, to provide soft start. The circuitry includes an oscillator for providing a periodic signal in which each cycle includes a rising portion followed by a falling edge to a low portion. Reference circuitry provides a varying reference signal. A comparator responds to the periodic signal and the varying reference signal, and provides a pulse output signal whose pulse width is proportional to the reference signal.

Abstract: A switching power converter for producing regulated D.C. power at two or more voltages. First and second regulation circuits including switching elements are connected across the secondary side of a transformer. A control circuit including a phase lock loop provides a first timing signal in leading relation to the AC input, and a delay circuit which provides a second timing circuit in delayed relation to the first timing signal. A logic circuit is responsive to the first and second timing signals to provide drive signals for the switching elements. The regulation circuits each include a first switching element having a power terminal coupled to the secondary winding and another power terminal is coupled to an intermediate node. A second switching element has a power terminal coupled to the intermediate node and another power terminal coupled to a common node. An inductor is coupled from the intermediate node to an output node.

Abstract: An integrated gate drive controller for a synchronous rectifier circuit which minimizes secondary side stray inductance effects in the synchronous transistor branches by controlling overlap of the gate drive signals to the synchronous transistors.

Abstract: A switching power converter, comprising: a secondary side transformer winding having first and second ends across which an AC voltage is inducible; a first regulation circuit including: a first switching element having a power terminal coupled to the first end of the secondary side transformer winding and another power terminal coupled to a first intermediate node; a second switching element having a power terminal coupled to the first intermediate node and another power terminal coupled to a common node; and a first inductor coupled from the first intermediate node to a first output node; a second regulation circuit including: a third switching element having a power terminal coupled to the second end of the secondary side transformer winding and another power terminal coupled to a second intermediate node; a fourth switching element having a power terminal coupled to the second intermediate node and another power terminal coupled to the common node; and a second inductor coupled from the second intermediate

Abstract: A switching power converter for producing regulated D.C. power at two or more voltages. First and second regulation circuits including switching elements are connected across the secondary side of a transformer. A control circuit including a phase lock loop provides a first timing signal in leading relation to the AC input, and a delay circuit which provides a second timing circuit in delayed relation to the first timing signal. A logic circuit is responsive to the first and second timing signals to provide drive signals for the switching elements. The regulation circuits each include a first switching element having a power terminal coupled to the secondary winding and another power terminal is coupled to an intermediate node. A second switching element has a power terminal coupled to the intermediate node and another power terminal coupled to a common node. An inductor is coupled from the intermediate node to an output node.

Abstract: A power converter including a switching transformer having a primary winding and a secondary winding, the secondary winding having first and second voltage nodes across which a winding voltage having a variable duty cycle and phase is impressed; a first synchronous rectifier transistor coupled from the first voltage node to a common node; a second synchronous rectifier transistor coupled from the second voltage node to the common node; and a driver circuit operable to receive the winding voltage and produce first and second drive signals to the first and second synchronous rectifier transistors, respectively, the first and second drive signals leading the phase of the winding voltage.

Abstract: A high speed, high power bipolar transistor has a planar emitter structure having a central area and outer peripheral areas. The doping concentration in the central area is reduced as compared to that of the outer areas to reduce the injection efficiency at the central area of the emitter region. A low doped region of conductivity type opposite to that of the emitter surrounds the emitter area and can fully deplete to spread out the field to permit high voltage breakdown for the device. A novel process of manufacture is used wherein the doping concentration across the emitter area is controlled by diffusing the emitter through a pattern of elongated or rectangular or other cross-section masking islands which have closer spacing in the center of the emitter region to produce a lower average doping concentration in the center of the emitter than in the outer peripheral regions of the emitter.