Darshan Hiranandani : Looking for help with the design of a current limiting circuit with a target of 3.0A. Any advice or tips?

Hey everyone, I’m Darshan Hiranandani, currently working on designing a current limiting circuit aimed at maintaining a current of 3.0A. Do any of you have valuable advice, tips, or insights to share regarding this project? Your expertise would be greatly appreciated!

Hi Darshan!

I’d use a buck regulator with built-in configurable current limiting. 3 A may be too high for a linear regulator (if VIN >> Vout), but I don’t have enough information about your circuit to say for certain.

Note that if you’re making a constant current load, a buck with built-in limiting likely won’t work. From my experience they limit output current, not input current. I assume you’re making a constant current source, but I thought I’d mention it.

Make sure you pay attention to heat dissipation and proper trace widths. 3A generates some heat!

We need more information on what the application is. Is it for driving LEDs? Is it overload protection? I’m sure there is a chip to do what you want, I just don’t know what to suggest.

Are you looking for a power supply circuit that limits current to a maximum of 3A, a power supply circuit that outputs a constant 3A, or something else?

What voltage is this at? That affects what chips are suitable a lot. If low (5V and under) there are a lot of good chips designed for USB. Something like Diodes Inc AP22655, but there are loads available. Also depends on the use case - but if it’s for a current-limited output then something like the above is probably what you want.