Maximum LED loop length?

Denis Alain1

Hi,

I would like to use a LED driver to drive a LED rings with a very short 1A pulse (1A for 700us at 60Hz cycle). The LEDs will be soldered on an ALU core.

Is-it possible to have the TI controller at about 2 feet from the LEDs ring? Or I need to place it directly on the ALU core with the LEDs. Probably to avoid loop problems (instability), the controller should be near the LEDs on the ALU core. We would prefer to solder the controller on the cupper PCB to decrease the complexity of the ALU core ($ issue, mechanic issue).

Thanks,

Denis.

over 9 years ago

0 David Zhang over 9 years ago

TI__Expert 3495 points

Denis:
Yes, it is possible to have the controller 2 feet from the LED ring and the converter is still stable. But you may want to keep the loop short to avoid the extra voltage drop across the wires.
David Zhang

0 Denis Alain1 over 9 years ago in reply to David Zhang

Intellectual 600 points

Thanks for your answer.
Is the voltage drop would be the only problem I may expect if I use a "very" long loop for a LED driver?

For example, if I design a LED circuit for a pedestrian bridge (another project I worked on), what would be the maximum length we can expect from this topology (rule of thumb)?
Best Regards,
Denis

0 David Zhang over 9 years ago in reply to Denis Alain1

TI__Expert 3495 points

Denis:
I don't have the number of the maximum LED loop length. I know 2 feet is OK because I have tried something like that. The voltage drop is not the only concern. There are distributed inductance and capacitance you have to pay attention to for very long loop length.
David Zhang

0 Denis Alain1 over 9 years ago in reply to David Zhang

Intellectual 600 points

Thanks David,

At least I know that it's possible. I will prototype it before to start the schematic.

Best Regards,

Denis

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Maximum LED loop length?