Electronic power converter with ground referenced lossless current sensing

摘要

A current sensing circuit for an electronic power converter having an inductor that is not referenced to ground is configured to provide an output signal that is referenced to ground and is proportional to the current flow between the inductor and a load in an electrical power system. The current sensing circuit includes outputs associated with a voltage of the inductor, a current source circuit, a current steering circuit responsive to the voltage outputs and a level shifting circuit.

主权项

1. An electrical power converter comprising:
power converter circuitry including an inductor, wherein the inductor is not referenced to electrical ground; and a current sensing circuit connected to the inductor, the current sensing circuit comprising:
at least one element arranged to have a voltage proportional to a voltage across the inductor when the power converter circuitry is operating;first and second voltage outputs associated with the at least one element;a current source circuit;a current steering circuit comprising first and second matched active elements each connected to the current source circuit and to the first and second voltage outputs, each of the first and second active elements configured to receive a current from the current source circuit and provide a current output that is responsive to the first and second voltage outputs; anda level shift circuit receiving the output from each of the first and second matched active elements and configured to provide an output signal that is referenced to ground, the output signal being proportional to a current flowing between the inductor and an electrical load.