Isolated power transfer with integrated transformer and voltage control

Abstract

An isolated power transfer device has a primary side and a secondary side isolated from the primary side by an isolation barrier. A secondary-side circuit includes a rectifier circuit coupled to a secondary-side conductive coil. The secondary-side circuit includes a first resistor coupled to a first power supply node and a terminal node. The secondary-side circuit includes a second resistor coupled to the terminal node and a second power supply node. The secondary-side circuit includes a first circuit to generate a feedback signal in response to a reference voltage and a signal on the terminal node. The feedback signal has a hysteretic band defined by the first resistor and the second resistor. The secondary-side circuit is configured as an AC / DC power converter that provides, on the first power supply node, an output DC signal having a voltage level based on a ratio of the first resistor to the second resistor.

Description

BACKGROUNDField of the Invention[0001]This invention relates to isolation technology and more particularly to providing power across an isolation barrier.Description of the Related Art[0002]Referring to FIG. 1, a conventional high-power system (e.g., a system having a power level greater than approximately 1 W) uses a power converter including standard transformer 109, e.g., a discrete transformer with a ferrite core and high efficiency to transfer power across the isolation barrier. Depending on the complexity of the drive circuitry, the conventional high-power system may achieve power transfer efficiencies of approximately 70%-approximately 95%. In order to regulate the output voltage, communications channel 104 provides any necessary feedback signals across the isolation barrier. Although the standard transformer implementation is efficient, the size and cost of the standard transformer implementation may be prohibitive for use in some applications. Thus, low-cost, isolated power...

AI Technical Summary

Benefits of technology

The patent describes an isolated power transfer device that includes a primary side and a secondary side that are isolated by an isolation barrier. The device includes a feedback circuit that generates a hysteretic band based on the resistance of two resistors and a primary-side power supply. The feedback circuit controls a DC output voltage that is based on a reference voltage and a signal on the secondary-side. The device includes a transformer with a primary coil and a secondary coil that transfer power between the primary and secondary sides. The isolated power transfer device has a small size and is suitable for use in high-temperature environments. The technical effects of the invention include improved isolation between the primary and secondary sides, reduced power loss, and improved stability and reliability.

Problems solved by technology

Although the standard transformer implementation is efficient, the size and cost of the standard transformer implementation may be prohibitive for use in some applications.

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