Abstract: The present application relates to electronics and in particular to switch drive circuits and more particularly to galvanically isolated switch circuits with power transfer from the switch driver input side to the switch side. More specifically, the present application provides a switch drive circuit using a single transformer to transfer control signals to a secondary side for control of the switch along with power to a secondary side circuit to drive the switch in response to the control signals. By detecting the control signal first before drawing current, the effects of leakage inductance in the transformer are reduced.

Abstract: The present application relates to an isolated drive circuit, of the type commonly employed as high side drivers, for providing a drive signal to a semiconductor switch. The isolated drive circuit comprises a transformer with primary and secondary windings. The circuit further comprises a primary side circuit having a plurality of switches arranged in a bridge configuration with the primary winding positioned across the output of the bridge and a secondary side circuit connected to the secondary winding of the transformer and having a drive circuit output for providing a drive signal to the semiconductor switch. The advantage of this approach is that the entire circuit can be constructed as a module for use as a single component on a circuit board without requiring additional external components.

Abstract: The present application relates to electronics and in particular to switch drive circuits and more particularly to galvanically isolated switch circuits with power transfer from the switch driver input side to the switch side. More specifically, the present application provides a switch drive circuit using a single transformer to transfer control signals to a secondary side for control of the switch along with power to a secondary side circuit to drive the switch in response to the control signals. By detecting the control signal first before drawing current, the effects of leakage inductance in the transformer are reduced.