CURRENT SAMPLING METHOD AND CURRENT SAMPLING APPARATUS FOR ISOLATED POWER CONVERTER

摘要

Disclosed are a current sampling apparatus and a current sampling method for an isolated power converter. The isolated power converter includes a square wave generator, an isolated transformer, and a primary side filter circuit coupled therebetween. The current sampling apparatus includes: a first sampling circuit coupled to the primary side of the isolated transformer and sampling a total current of the primary side of the isolated transformer and outputting a first sampling current; and a shunt circuit receiving the first sampling current. The shunt circuit includes a first shunt branch circuit through which the first sampling current is transformed into an excitation sampling current and a second shunt branch circuit through which the first sampling current is transformed into a current to be sampled.

主权项

1. A current sampling apparatus for an isolated power converter, the isolated power converter comprising a square wave generator, an isolated transformer, and a primary side filter circuit coupled therebetween, the current sampling apparatus comprising:
a first sampling circuit coupled to the primary side of the isolated transformer and sampling a total current of the primary side of the isolated transformer and outputting a first sampling current; and a shunt circuit receiving the first sampling current and comprising:
a first shunt branch circuit through which the first sampling current is transformed into an excitation sampling current, the excitation sampling current being in proportion to an excitation current passing through an excitation inductor at the primary side of the isolated transformer; anda second shunt branch circuit through which the first sampling current is transformed into a current to be sampled, the current to be sampled being in proportion to a transmitted current transmitted from the primary side of the isolated transformer to a secondary side of the isolated transformer.