Abstract: A method and circuit for driving power transistors arranged in series in a half bridge configuration allowing for excessive negative swing of an output node between the transistors in the half bridge configuration. The series transistors are connected between a first voltage source and a common potential. A second voltage reference source is also provided. A terminal is connected to a common point coupled to anodes of intrinsic diodes of driver circuits for the power transistors. The second voltage source is connected between the common potential and the terminal so as to shift the level of the common point such that the intrinsic diodes will not forward bias due to negative output node transients generated by diode forward recovery and stray inductances. The circuit of the invention can also be incorporated in an integrated circuit including a single chip, e.g., a silicon chip.

Abstract: A polysilicon field ring structure is used to eliminate any type of unwanted surface current leakage in an integrated power chip having high voltage and low voltage areas and enclosed in a plastic housing. All P-type diffusions not biased to the ground potential are surrounded by rings biased to the supply potential, and all N-type diffusions not biased to the supply potential are surrounded by rings biased to the ground potential.