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LM3434: obsolete, please advise on replacement

Federico Papparotto35
Prodigy 200 points

Part Number: LM3434

Dear all,

could you please advise on the best replacement for LM3434, which is now obsolete? It needs to drive currents up to 36Amps. 

Some specs:

Operating Input Voltage : 12VDC – 24VDC
Buck topology CCM
I (led) max : 32Amp
Analog LED current adjust - Tie to an external reference to adjust the average LED current
En – Enable pin
DIM – Digital Input for dimming the LED (control the DIM FET (shunt))
Soft start
Longevity > 6 years

 

Thanks,

Federico Papparotto

  • 0
    TI__Expert 3920 points
    Hi Federico,

    Please check TPS92641 for shunt-FET PWM dimmable synchronous buck LED controller.
    Thank you!
  • 0 in reply to Issac Hsu
    TI__Prodigy 200 points
    Hi Issac,

    Thank you for your answer. I have further questions on this.

    I can see from the examples in the data sheet that they specify a relatively low LED forward current (~1Amp) ,

    what makes this controller to be suitable to drive LED currents of 32Amp?

    • Shall I connect special circuity to the FET Gates pins (HG,LG) to support LED high currents ?
    • Does the evaluation board supports LED currents of 32Amp ?

    Thank you,
    Federico Papparotto
  • 0 in reply to Federico Papparotto35
    TI__Expert 3920 points
    Hi Federico,

    We have a reference design PMP8016 shows the device operating for a 20 A output.
    However, we do not have any reference design with 32 A.

    You can compare the gate drive strength of LM3434 and TPS92641.
    In fact, TPS92641 gate drive strength might be a little bit stronger than that of LM3434.
    If needed, I believe external totem-pole gate driver could help for higher current output applications.

    Thanks!