Searching for LED driver capable of outputting at 1A or higher

Discussion in 'General Electronics Chat' started by Orien Walker, Aug 1, 2016.

  1. Orien Walker

    Thread Starter New Member

    Aug 1, 2016
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    Working on a light project and am having trouble finding a LED driver capable at outputting at 1 to 2 amps. mostly finding in the 20mA range. Suggestions, ideas?
     
  2. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    Welcome to AAC!
    What is the LED spec (voltage)?
     
  3. Orien Walker

    Thread Starter New Member

    Aug 1, 2016
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    the typical forward voltage is 2.95 at 1.05A.
    It has a Max Amp rating of 3A and i want to run it at 2 Amps for the Lumens i'm aiming for.
    I've been looking at microchip drivers and the max output i can find is 800mA.
     
  4. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Do you want an IC and have to roll your own LED driver (PCB,extra components,etc..) or something off the shelf (plug and play)?
    AC input? DC input?
    voltage of supply?
    Is this just for a single LED or multiples in series?
    Require dimming?
    Dimming signal?
    agency approvals? (FCC, UL,etc..)

    and any other details you have..
     
  5. Orien Walker

    Thread Starter New Member

    Aug 1, 2016
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    Trying to run system on 3V DC battery supply.
    Single LED, looking at the cree Xlamp XP-L.
    Dimming would be nice.
    not too concerned with agency approval atm.
     
  6. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    3V battery... 2.95Vf LED... See a problem there?

    Not to mention 2.95Vf is it 1A.. at 2A its about 3.15V
     
  7. Orien Walker

    Thread Starter New Member

    Aug 1, 2016
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    I see that, but the drivers I'm looking at boast no boost losses, so I'm under the impression that will work. Unless i am understanding that wrong.
    If i am and that just wont work, i can run it at 6V and use two of them in parallel. Using CR123 batteries if that helps clarify anything.
    Isnt the point of the driver to boost the voltage to drive LEDs from smaller supplies?
     
  8. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Not necessary...
    An LED driver in general provides a fixed output current to power the LEDs.. LEDs need to be fed a constant current (at a voltage higher than their Vf)...

    Now a "boost" LED driver will also boost the input voltage and provide the fixed output current for the LED..

    With small LEDs (20mA,etc..) you typically use a resistor to "feed" the proper output current to the LED.. Hence why you always see a resistor in an indicator LED circuit..
    With "higher current" LEDs the resistor can still be used BUT it will probably be dissipating much more wasted heat to provide the required output current and just more inefficient compared to a LED driver..

    Seems like you might want to go back and study up on the basics before going further..

    This is what you need if you want an IC
    http://www.linear.com/products/step-up_(boost)_led_drivers
    Something like an LT3477 should work or LT3478.. But there are many others out there..
    You just need to nail down your requirements..
     
  9. Alec_t

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    Here's a possible driver IC for a DIY driver.
     
  10. Orien Walker

    Thread Starter New Member

    Aug 1, 2016
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    http://www.cree.com/LED-Components-and-Modules/Products/XLamp/Discrete-Directional/XLamp-XPL
    http://ww1.microchip.com/downloads/en/DeviceDoc/mic2843.pdf
    This is the LED I want to use and the driver I found. IF I run the driver in High Current Parallel operation (Roughly 1.5A output) with a 6V supply Would that work?
    I have experience in circuitry but most of my experience is in coding and this is my first time dealing with "high current" LEDs and LED drivers, So, I'm a little unsure on exactly how a LED driver works and what parameters to focus on.
     
  11. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Input voltage of 3-5.5Vdc... (yes absolute Max input is 6V but don't design to that)
    But yes running them in "high current parallel mode" will give you 6 times the output current..
    There are much better solutions vs the one you found..

    Do you have size limitations/requirements for this?
    Would you like something that doesn't require a circuit board/soldering/extra components,etc..?
    Is this for a flashlight or similar tightly packaged device?
    Are you skilled in thermal management? (keeping an LED cool may be a big challenge for you)
    How long do you need it to last on batteries?

    and so many other questions I have to properly steer you in the right direction..
    You need to provide as much information as you can... This is Engineering.. We need details... (all of them if possible and at one time as we HATE being spoon fed bit by bit)
     
  12. Orien Walker

    Thread Starter New Member

    Aug 1, 2016
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    ok, let me try and do better here.
    This is for a flashlight like device so i am shooting for a small footprint for the components/board. circuit boards/soldering/ extra components are not an issue, i am not skilled in thermal management but i do have a mechanical engineer working on this project as well so we might have that covered, but input on the matter is welcomed. Battery life is up in the air, although we are using CR123 batteries. so either in series at 3V for longer battery life or in parallel at 6V. If need be we can sacrifice battery life for the extra voltage. We are trying to light the LED mentioned before near its max output, so somewhere in 1.5 to 2.5A. Most of these drivers have PWM pins to control the dimming and i can control that with code and an external microcontroller.
     
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