How to build a 2.5A constant current?

Luong_Hai_Vietnam

Other Parts Discussed in Thread: LM3407, LM3406, TPS62130, TPS92512, LM3409, TPS92640

I used to make some constant current supplies such as LM3407, LM3406 driver but all of them below 1.5A. Is there a TI's IC met 2.5A or combinable ICs helped me do this?

I'm designing a Cree-XML2 Drivers that need a 3A constant current. I just need a greater 2.5A supply for the project.

over 9 years ago

0 Chris Glaser over 9 years ago

TI__Guru**** 150590 points

I drive a similar LED in this reference design: http://www.ti.com/tool/pmp9762 You can do the same thing with the same TPS62130 IC.

0 Luong_Hai_Vietnam over 9 years ago in reply to Chris Glaser

Prodigy 40 points

Can TPS92512 do this? I have tried this IC but the output current not depend on IADJ pin. I don't know why it is :(

0 Issac Hsu over 9 years ago in reply to Luong_Hai_Vietnam

TI__Expert 3920 points

Hi Hai,

TPS92512 can support at most 2.5 A average LED current output.

The pin voltage on IADJ should be within 0.18 V to 1.8 V in order to get a linear current adjustments.

ISENSE pin voltage = IADJ pin voltage / 6 within the range of 0.18 V to 1.8 V on IADJ.

Once the voltage on IADJ above 1.8 V, ISENSE pin voltage will be clamped at 0.3 V.

If you really need a 3 A output, I would suggest you consider LM3409 (P-FET buck controller) or TPS92640 (synchronous N-FET buck controller).

I hope the above helps!

Thank you!

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How to build a 2.5A constant current?