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AN-1208 Overcurrent Protection Device
Introduction
In this application note, we’ll build an overcurrent protection device. Overcurrent
protection is protection against excessive currents or current beyond the acceptable current
rating of the device. To protect downstream loads, the point of overcurrent protection should
occur at the FET switch.
An overcurrent protection device can be implemented using a GreenPAK
™ 3 SLG46116V chip.
The SLG46116 includes a P-FET Power Switch designed for load switching applications. The P-
FET Power Switch can be controlled internally via the ON digital input of the P-FET Power
Switch component in GreenPAK Designer, allowing the user to generate integrated mixed-
signal control circuits.
The P-
FET Power Switch contains a 28.5mΩ RDSON, 1.25 A P-channel MOSFET with fixed
slew rate control. The device has a built-in soft-start, which controls the output rise time. This
minimizes inrush current when the switch is enabled.
For this implementation, the protected circuit is connected to the voltage supply via the
SLG46116V chip P-FET. When the current in the protection circuit reaches the preset maximum
current rating value, the GreenPAK device can almost instantly turn off the P-FET power switch
and s
top the flow of “overcurrent”.
Figure 1. Overcurrent Protection Application Circuit with the SLG46116V chip
