Current limited buck power supply
AssigneeInternational Rectifier Corporation
InventorsAjit Dubhashi, Vijay Bolloju, Bertrand Vaysse
Life of this patent
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Abstract
A novel power supply control circuit topology uses a standard power supply controller to control a high side switch in an electronic circuit. A feedback voltage referenced to ground (or negative bus level) is level-shifted to a high side controller by means of a diode/capacitor/resistor network. Power to the high side controller is supplied by using the feedback output voltage. The circuit can be used instead of conventional flyback converters, particularly in low voltage applications. The circuit requires fewer pins on the transformer/inductor, leading to lower cost and size, particularly as compared to prior art flyback converters. Lower voltage rating required for the switch reduces noise and losses in the device.
Claims8
A buck converter power supply comprising:
- a first power semiconductor switching device coupled to a voltage source;
- a controller for controlling the switching operation of the first power semiconductor switching device;
- a second semiconductor device coupled in series with the first power semiconductor switching device to ground, there being a common node between the first and second semiconductor devices;
- an inductor coupled between the common node and an output capacitor, the output capacitor being connected between an output terminal of the power supply and ground;
- the controller being referenced to the common node;
- a feedback voltage being provided from the output terminal referenced to ground through a level shifting circuit to provide a control signal to the controller, the control signal being referenced to the common node;
- and
- the level shifting circuit comprising a diode/resistor/capacitor network.
Dependencies are inferred from the claim text.