AN606 - Vishay

AN606 Current Sensing Power MOSFETs

AND PRINCIPLE OF OPERATION D2PAK-5 D (Tab, 3) G (1) (4) KELVIN w 1 2 3 4 5 w SENSE (2) w S (5) .D SENSE G D S KELVIN N-Channel MOSFET Dividing the MOSFET cells in a known ratio creates two paths that share the drain-source current. The path with the smaller number of cells constitutes the sense current, which is much smaller than the current.

Features

such as overcurrent and/or short circuit. This approach offers the freedom and flexibility of control-circuit design, though the accuracy of measurement is not suitable for current-control applications. Virtually any power MOSFET from the Vishay Siliconix product range can be supplied with a current-sensing feature. www.vishay.com 4 Document Number: 71991 17-Dec-03 .