High efficiency backup-power circuits for switch-mode power supplies

摘要

Disclosed are novel interconnections of a coupling circuit and an energy storage device which enables the storage device to provide back-up power for a switching power supply without requiring the device to store or output high voltage, and which enables full utilization of the energy stored in the device. In exemplary embodiments, the combination of the coupling circuit and the energy storage device may be coupled between the input and output of the switching power supply (e.g., between the non-ground terminals of the input and output ports of the switching power supply). The coupling circuit is configured to couple power from the energy storage device to the input of the switching power supply when the input power source is not provided to the switching power supply, and optionally to couple power from the input power source to the energy storage device when the input power source is provided.

主权项

1. A power supply comprising:
an input port to receive a source of input power, the input port having a first terminal and a second terminal; an output port to provide output power, the output port having a first terminal and a second terminal; a switching power supply having an input coupled to the input port to receive input power and an output coupled to the output port to provide output power; a selected circuit node having a potential, wherein, when input power is provided to the input port, the potential difference between the first terminal of the input port and the selected circuit node has the same polarity as the potential difference between the first and second terminals of the input port, but is less in magnitude; and a circuit combination of a coupling circuit and an energy storage device, a first terminal of the circuit combination being coupled to the first terminal of the input port, and a second terminal of the circuit combination being coupled to the selected circuit node, the circuit combination being configured to couple energy from the energy storage device to the input of the switching power supply when input power is not provided at the input port.