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TPS92622-Q1: Software Programmable Constant Current LED Driver

Matthew Lynch
Prodigy 20 points
Part Number: TPS92622-Q1
Other Parts Discussed in Thread: TPS92620-Q1, , TPS92629-Q1

Hi all,

I need a constant current controller for an LED lighting application The specs as it stands now:

48V input

32-48V output (48 preferred, but that seems hard to find)

Software adjustable current - This is a lighting system for a vision system with a very fast exposure time, so I can't use PWM dimming, as it could cause uneven exposure between frames, but I do want software to be able to set the current through the LED's to adjust brightness

75 mA max output or higher

2 independent channels, but I don't mind using 2 parts if necessary.

I've been looking around for a day or so and am really struggling to find something that meets my needs. The part I mentioned in the title, for example, looks like it has a fixed current set by an external resistor - Does TI make a part that is similar, but with software-adjustable current?

  • 0
    TI__Expert 6690 points

    Hi Matthew,

    What do you mean "software-adjustable current"? like this device can support the communication? could you share more details?

    and what is your application? the voltage range is not common.

    BR,

    Hailee.

  • 0 in reply to Hailee Xu
    Prodigy 20 points

    By software adjustable, I mean that the software can do *something* to adjust the brightness level. I was imagining either a PWM control (that doesn't actually PWM the LED's or I2C control, but other options are ok, too. The application is that we need to backlight an object and get images to do some image processing. The need for 48V is that we need to power a string of 16 LED's, which is a bit under 48V to drive. The 32 is with the idea that we could change the length of the strings if needed, but that would increase the current requirements significantly.

  • 0 in reply to Matthew Lynch
    TI__Expert 6690 points

    Hi Matthew,

    For two channel LED solutions, TPS92622-Q1 could be recommended with two PWM pins, and this device can support up to 150mA of output current per channel, but the input voltage needs to be paid more attention. If the current requirement is higher, the TPS92620-Q1 could be an option, the output current can be increased to 250mA per channel.

    BR,

    Hailee,

  • 0 in reply to Hailee Xu
    Prodigy 20 points

    I explicitly DO NOT want the PWM signal to show up on the output (as that part seems to indicate it does). I want to adjust the current through the LED's NOT PWM it. This is for imaging with short exposure rates, so PWM signals on the output could cause uneven exposure. Are there any controllers you offer that provide adjustable current output? It looks like the current on the part you suggested is defined by a resistor, rather than being software adjustable..

  • 0 in reply to Matthew Lynch
    TI__Expert 6690 points

    Hi Matthew,

    If you don't want to use PMW dimming. TPS92629-Q1 could be an option with the ADIM pin, the customer can use a PWM signal to achieve the analog dimming function. Is it acceptable for the customer? 

    BR,

    Hailee.

  • 0 in reply to Hailee Xu
    TI__Expert 6690 points

    Hi Matthew,

    Since it's been a long time I haven't heard from you, I will close this post.

    If you have any other questions, please create a new one.

    Thanks!

    BR,

    Hailee.