System and method of sensing current in a power semiconductor device

摘要

A current sensor to be connected in series with a power semiconductor device between a voltage supply terminal and ground. The current sensor includes a first terminal to be coupled to the power semiconductor device, a second terminal to be coupled to one of the voltage supply terminal and ground, and a current mirror. The current mirror includes a first MOSFET and a second MOSFET each having a source, a drain, and a gate. The source of the first MOSFET is connected to the source of the second MOSFET and to the second terminal, the drain of the first MOSFET is connected to the first terminal, and the gate of the first MOSFET is connected to the gate of the second MOSFET.

主权项

1. A current sensor to be connected in series with a power semiconductor device between a voltage supply terminal and ground, the current sensor comprising:
a first terminal to be coupled to the power semiconductor device; a second terminal to be coupled to one of the voltage supply terminal and ground; a current mirror that includes a first metal oxide semiconductor field effect transistor (MOSFET) and a second MOSFET each having a source, a drain, and a gate, the source of the first MOSFET being connected to the source of the second MOSFET and to the second terminal, the drain of the first MOSFET being connected to the first terminal, and the gate of the first MOSFET being connected to the gate of the second MOSFET; and a current sense and bias circuit connected to the drain of the first MOSFET and the drain of the second MOSFET to maintain a voltage level at the drain of the first MOSFET and the drain of the second MOSFET at substantially a same level.