• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 63 subscribers
  • Views 256 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LM3410: LM3410XMY/NOPB- Unusual circuit behaviour.

Peter Seetal
Prodigy 110 points
Part Number: LM3410


Hello,

I'm using one of your LED Driver ICs, LM3410XMY/NOPB.  I've been having some quite bizarre circuit behaviour and thought it worth reaching out to you on recommendations with the circuit construction.

I was simply with the intention to drive a series x4 LEDs, with x4 duplicate instances of a basic LM3410XMY/NOPB circuit to drive x4 White, x4 Red, x4 Green, and x4 Blue LEDs. Attached is my LED Drive circuit for reference.

My circuit input Voltage is 5V.

When initially powering the circuit, I had no load on the output of any of the x4 duplicate instances of LM3410XMY/NOPB circuit, and it seems each o the ICs may actually have "self-destructed" for lack of a better expression. (Happy to be wrong here if you think something else may be at work).

My question today, to drive x4 LEDs in series and considering my circuit below, do you have any immediate recommendations for stable circuit operation?  I imagine I'll probably be wanting to add in some output overvoltage protection via a Zener Diode, but I'd be interested in hearing your general thoughts.

Many thanks,LED Drive Circuit (LM3410XMY).pdf

  • 0
    Prodigy 110 points

    Also worth asking is if there are any other ICs you would recommend that may work simply and well for this application. I'm happy with single-chip solutions also as this design may increase in density. Reducing external component count will also be a free win.

    I believe finally I will only require up to 100mA drive per LED chain and up to 20V output voltage.

  • +1 in reply to Peter Seetal
    TI__Mastermind 18890 points

    Hello Peter,

    The LM3410 should be able to do what you want if the output voltage is 20V or less.  You have to operate your circuit with a load on it otherwise you will damage the part.  The reason is that it's a current regulator and if you have an open circuit without any zener diode to clamp the voltage then the output will rise until it exceed the voltage of the part (24V).  The zener needs to clamp the voltage to 21V.  Please see section 8.1.1.7 of the data sheet.

    Thanks Tuan