LM2596 12V Fixed - Vout dropping when load is applied

Caitlin Flowers

Other Parts Discussed in Thread: LM2596

Hello!

So I am using a LM2596 Buck Converter to output 12V. My Load circuit is a DC fan with an impedance of ~60 Ohm and drawing .22A

My issue is this.

Without the load, the regulator outputs 12V as expected, but as soon as we connect the load that output voltage drops to ~4V

Does anyone have any suggestions as to why that might be happening?

Thanks!

0 Frank De Stasi over 8 years ago

Please send you schematic and layout.

Is this a Webench design?

0 Caitlin Flowers over 8 years ago in reply to Frank De Stasi

It is not a webench design, though I did just go play around with it. Definitely a tool I'll use in the future.

I'm still interested in solving my current problem though.

Here's my schematic. I'm breadboarding right now so I used inductor and capacitor values as close to the recommended values I could get.

All components meet the voltage/current requirements.

My load is a 12V DC fan that draws .22 A typically.

0 Frank De Stasi over 8 years ago in reply to Caitlin Flowers

It may be a layout issue. You need a good PCB for a switcher.

I can send you an EVM, free of charge, to help you get started with a solid PCB platform.

You can modify it to meet your requirements.

Please send you name, phone, and shipping address to the following email: simpleswitcherapps@ti.com

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