Isolated drive circuitry used in switch-mode power converters

• US 6,791,851 B2
• Filed: 08/26/2003
• Issued: 09/14/2004
• Est. Priority Date: 02/01/2001
• Status: Expired due to Term

• Current Assignee: Bel Power Solutions Inc.
• Original Assignee: DI/DT, Inc. (ABB Limited)
• Inventors: Brkovic, Milivoljee S.
• Primary Examiner(s): HAN, YOUNGHUIE JESSICA
• Application Number:
  US10/648,659
• Publication Number:
  US 20040047164A1
• Time in Patent Office: 385 Days
• Field of Search: 323/247, 323/276, 323/277, 361/79, 361/87, 361/93.1, 361/93.6, 363/56.01, 363/56.02, 363/56.03, 363/56.07, 363/56.1
• US Class Current: 363/56.03
• CPC Class Codes: H02M 1/08 Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
• CPC Class Codes: H02M 1/088 for the simultaneous control of series or parallel connected semiconductor devices
• CPC Class Codes: H02M 1/38 Means for preventing simultaneous conduction of switches

Abstract

A drive transformer and associated circuitry for providing power and appropriate delays to primary switches and synchronous rectifiers in switch-mode power converters in a full-bridge topology. The invention takes advantage of the leakage inductances of the drive transformer windings as well as the input capacitance of the primary switches (MOSFETs) to provide the delays. No separate circuitry is needed to provide such delays, thereby providing reliability. Exemplary embodiments further disclose means to disable or enable the primary winding from a condition sensed on the secondary side even with a control and feedback circuit located on the secondary side. The invention further discloses means to use one drive transformer winding to control two switches completely out of phase.

Claims

1. A method for disabling a switch-mode power converter having a drive transformer winding connected to a switch conduction control circuit and said switch conduction control circuit referenced to the input of the power converter from a condition sensed on the output of the power converter, the method comprising the steps of:

sensing a condition on the output of the power converter that requires the power converter to be disabled;

shorting a drive transformer winding connected to circuitry referenced to the output side of the power converter;

detecting excessive current across a drive transformer winding connected to said switch conduction control circuit connected to the input side of the power converter; and

sending a signal to disable the switch conduction control circuit, thus disabling the converter.

2. A method for disabling a switch-mode power converter having a drive transformer and a switch conduction control circuit referenced to the output of the power converter from a condition sensed on the input of the power converter, the method comprising the steps of:

sensing a condition on the input of the power converter that requires the power converter to be disabled;

shorting a drive transformer winding connected to circuitry referenced to the input side of the power converter;

detecting excessive current across a drive transformer winding connected to the switch conduction control circuit connected to the output side of the power converter; and

sending a signal to disable the switch conduction control circuit, and thus disabling the converter.