Renesas AN-1208 Quick Start Manual

Overcurrent protection device

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 stop the flow of "overcurrent".

Figure 1. Overcurrent Protection Application Circuit with the SLG46116V chip

Table of Contents

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Page 1 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.
Page 2 R1 in Figure 1, which is connected between the protected circuit and GND, and by selection of the IN- Vref value of ACMP, which has 24 internal reference sources (50 mV – 1200 mV) and VDD/3, VDD/4, PIN 4. © 2022 Renesas Electronics Corporation...
Page 3 0.1 F capacitor from VOUT pin to the GND. Conclusion An overcurrent protection device can be easily implemented using a GreenPAK 3 that includes a P-FET Power Switch. It has low power consumption and few external components. © 2022 Renesas Electronics Corporation...
Page 4 Renesas' products are provided only subject to Renesas' Terms and Conditions of Sale or other applicable terms agreed to in writing. No use of any Renesas resources expands or otherwise alters any applicable warranties or warranty disclaimers for these products.