Abstract: An isolation circuit for use in a power plant having a first power supply that powers a first load and a second power supply that powers a second load. The first and second power supplies are cross-couplable via a first and second auxiliary path to allow the first power supply to power the second load and the second power supply to power the first load. The first power supply is subject to a reverse current by way of the first auxiliary path. The isolation circuit includes a first switch, located in the first auxiliary path, that substantially reduces the reverse current flowing into the first power supply thereby enhancing an isolation of the first power supply. A controller is, also, provided that monitors the first switch thereby enhancing a reliability of the power plant.

Abstract: A controller for a power switch having an isolated control terminal and coupled to a secondary winding of a drive transformer and a method of preventing spurious turn-on of the power switch. The controller includes: (1) a controllable switch, coupled between the secondary winding and the power switch, that alters a control voltage of the power switch in response to a characteristic of the secondary winding, and (2) a bias circuit coupled to the controllable switch and the power switch that provides a voltage differential between the controllable switch and the power switch to prevent spurious turn-on thereof.

Abstract: A controller for a power switch having an isolated control terminal and coupled to a secondary winding of a drive transformer and a method of preventing spurious turn-on of the power switch. The controller includes: (1) a controllable switch, coupled between the secondary winding and the power switch, that alters a control voltage of the power switch in response to a characteristic of the secondary winding, and (2) a bias circuit coupled to the controllable switch and the power switch that provides a voltage differential between the controllable switch and the power switch to prevent spurious turn-on thereof.

Abstract: An isolated MOSFET gate drive includes circuitry to provide a negative gate bias during the off time of the MOSFET to enhance its immunity to inadvertent turn-on. The bias is generated by a self contained two terminal passive network which may be "floated" at any potential with respect to ground. This bias is automatically generated through the action of the network to the gate drive waveform, eliminating the need for an external bias supply to provide this voltage. The bias supply is located locally, thus eliminating the need for long interconnects which may interfere with circuit operation. The bias network in one implementation is a combination of a capacitor and non-linear semiconductor device with a fixed voltage breakdown characteristic. This two-component implementation maintains the capability of producing systems with high packaging densities.

Abstract: A switching boost regulator, including auxiliary circuitry having an auxiliary switch and inductor connected to operate the regulator in a zero-voltage transition mode, achieves substantial efficiency improvement by limiting losses in the auxiliary circuitry dedicated to achieving zero-voltage transition operation. Loss reduction circuitry included with the auxiliary circuitry cooperatively operates to limit turn-on and conduction losses and to suppress ringing of the components of the auxiliary circuit.