Accuracy of LM3409-Q1

Tomohiro Nagasawa

Expert 1710 points

Other Parts Discussed in Thread: LM3409-Q1, LM3409, LM3402

Dear all

My customer want to high accuracy LED driver. And I suggest LM3409-Q1.

(Q1)Is it possible that the solution within ±5% accuracy of average LED current is designed using LM3409-Q1 ?

(Q2)Please teach another IC or solution.

＜spec＞

Vin=12V (damp 36V)

I led=0.5A (within ±5% Ta=-40～105℃）

LED：2×1strings

Regards

Tomohiro Nagasawa

over 10 years ago

0 David Zhang over 10 years ago

TI__Expert 3495 points

Nagasawa san:
It is hard to achieve +/5% LED current accuracy using LM3409. The Vcst reference voltage tolerance is over +/-5%. LM3402 can do +/-5% LED current with reference voltage tolerance +/-3%. But LM3402 is not Q graded.
David Zhang

0 Tomohiro Nagasawa over 10 years ago in reply to David Zhang

Expert 1710 points

David-san

Thank you for quick response.

For ±5% accuracy,they try to add external component and drive FET by EN pin.(See attached file)

Does this idea include the pending problem point?

I guess this response time is one of pending problem point.

Regards

Tomohiro Nagasawa

LM3409_Schematic.xlsx

0 David Zhang over 10 years ago in reply to Tomohiro Nagasawa

TI__Expert 3495 points

Nagasawa san:
Can you tell me your e-mail addrsss and I will send the response to your e-mail?
David Zhang

Power management

Power management forum

Accuracy of LM3409-Q1