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Dual Channel LED Driver

Manmohan M
Intellectual 280 points
Other Parts Discussed in Thread: PMP4484, TPS92515, TPS92641, TPS92640, TPS92518, LM3409

Hi,

I am looking for a dual channel LED driver with below specs, can you please help me find the right reference design/part no?

Input Voltage Range:                     90 V to 275 V

Input Freq:                                        50 Hz

Power factor:                                   >0.95

ATHD:                                                 <9%

Standby Power:                               <1 W

Output Channels:                            2

Pin:                                                   50W max (Per channel)

Output Voltage:                               30 V – 48 V (Per Channel)

Output Current:                              1.5 A Max (Per Channel)

Output Current Ripple:                 <30%

Dimming type:                                 PWM

Dimming Range:                             0 – 100 %

Protections:                                     OVP,UVP, Output No load, Output Short Circuit, Brown out Protection

  

Note:

Independent control of each channel to drive the load at required dimming level

Regards,

Manmohan M

  • 0
    TI__Mastermind 40520 points

    Hello Manmohan,

    Thank you for your interest in TI's LED drivers.

    I found the PMP4484 Reference Design for you to consider: 

    The power level and specifications are similar to your needs, and the you can disregard 4 of the 6 channels.  Modify the design and the remaining two channels for the increase in power to meet your requirements.  

    Aside from this, I invite you to peruse a wider set of designs here: http://www.ti.com/power-management/led-drivers/reference-designs.html#search?famid=480&vinmax=167.26,305&vinmin=3,143.97 and narrow down your search by adjusting the parameters available at the left side of the page.

    Regards,
    Ulrich 

  • 0 in reply to Ulrich Goerke
    Intellectual 280 points

    Hi Ulrich,

    Thank you for the quick response, 

    i have few queries on its performance,

    The Performance documentation on PMP4484 suggests:

    1. Efficiency is around 85% at F.L 

    Q. Is it because of 6 channel operation? Will the efficiency increase if my deign is for 2 channel operation?

    2. The performance curves shows that the output current is same for different PWM ?

    Q. Am i interpreting it wrong? i am not clear on the output current variation for different PWM inputs

    3. The Complete dimming curve is not shown

    Q. Can you please share any relevant document for the complete dimming performance? Can i have complete control of output current form 0 -100% ? 

    Is 0 dimming achievable with this solution?

    4. My requirement is 2 channel independent control of output current, is that possible with the suggested solution?

    5. Load current capability on each channel: atleast 1A

        Load Voltage : 30-48V

        Are these specs achievable ? if so what are the changes required?

    6. Is the any means of getting the Evaluation board as sample for quick performance evaluation and Prototyping?

    Regards,

    Manmohan M

  • 0 in reply to Manmohan M
    TI__Mastermind 28655 points

    Hello,

    This recently showed up under our support.  Are you still needing information regarding this?  PMP4484 has both an AC input portion and a DC/DC portion.  We support DC/DC however I also can help some with the AC portion if you need.

    Best Regards,

  • 0 in reply to Irwin Nederbragt
    Intellectual 280 points

    Yes please I am still looking for a solution with the requirements as mentioned in the thread.

  • 0 in reply to Manmohan M
    TI__Mastermind 28655 points

    Hello Manmohan,

    1. Efficiency is around 85% at F.L 

    Q. Is it because of 6 channel operation? Will the efficiency increase if my deign is for 2 channel operation?

    A:  Efficiency may go up a little at your output power.  A universal input PFC flyback running two buck converters is about this efficient for this power level.  This is lower power (30W) and the efficiency may be able to go up some at your power level depending on the design.

    2. The performance curves shows that the output current is same for different PWM ?

    Q. Am i interpreting it wrong? i am not clear on the output current variation for different PWM inputs

    A:  The Current remains the same, it's either off or on via the PWM command.  If the PWM is 50% and the current is the same as at 100% the light output will be 50% of full power.

    3. The Complete dimming curve is not shown

    Q. Can you please share any relevant document for the complete dimming performance? Can i have complete control of output current form 0 -100% ?

    A:  This depends on the driver used for the DC/DC converter.  You can look at many of our devices.  The TPS92515 may be a little small for this, the TPS92518 is a dual channel controller with SPI interface and external MOSFETs so it can be set up for your application.  The LM3409 is another part that is fairly simple to use.  And there is a synchronous part, the TPS92640/TPS92641 as well.

    Is 0 dimming achievable with this solution?

    A:  Yes, however some of the DC/DC solutions may require slight load or disable to get to true zero due minimum on-time or leakage currents.

    4. My requirement is 2 channel independent control of output current, is that possible with the suggested solution?

    A:  I would look at this as two designs, the universal input PFC creating a voltage rail and the DC/DC converter to drive LEDs.  The DC/DC converters will allow separate control for your two channels.

    5. Load current capability on each channel: atleast 1A

        Load Voltage : 30-48V

        Are these specs achievable ? if so what are the changes required?

    A:  Again, I would look at this as a new design.  PMP4484 is not high enough power for your application.  You'll need a different design for that.

    6. Is the any means of getting the Evaluation board as sample for quick performance evaluation and Prototyping?

    A:  There are EVMs for the DC/DC LED drivers you could try out.  PMPs are built only for collecting data and testing.  EVMs are for evaluating the IC.

    Your PFC and THD specification is fairly tight.  0.9 and 20% THD are typical.  In a universal input transition mode PFC it will be difficult to get much better.

    Best Regards,

  • 0 in reply to Irwin Nederbragt
    TI__Mastermind 28655 points

    Hello Manmohan,


    I haven’t heard back from you, I’m assuming you were able to resolve your issue.
    If not, just post a reply below (or create a new thread if the thread has locked due to time-out)

    Best Regards,