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TPS92663A-Q1: LED high pwm/current driver

Part Number: TPS92663A-Q1
Other Parts Discussed in Thread: TPS92518

Hi,

I need an advice for a driver/controller. We intend to use this LED cree.com/led-components/media/documents/ds-CMA1306.pdf

9V@900mA

The voltage is between 10V and 28. We need for version a a lamp with approx 20W and for version b approx 50W.
The brightness should be controlled by I2C or SPI interface (an additional controller might be possible)

What solution can you suggest?

Thanks

  • Hello Makes,

    I would like to get more detail of what you are trying to accomplish.

    Are you using one or more LEDs?

    "The voltage is between 10V and 28", is this the input voltage range or LED voltage range (one LED to three LEDs in series)?

    The LED you specify is 9V at 2.4A maximum with 18V and 36V options, note that this is the low end range of the LED Vf.

    What would be helpful is the Input voltage range, output voltage range or the LED configuration(s), output current range, number of LEDS (9V at xx mA, or other and series/parallel configuration) and any other design criteria you are looking to include.

    We have three SPI interface parts, the TPS92518 dual channel buck converter, the TPS92520 dual channel synchronous buck converter and the TPS92682 multi topology for boost, boost to battery (buck boost), SEPIC.

    Best Regards,

  • Hello Irwin,

    thank you for your reply. I'm using >1 leds. 10V and 28 is the min and max voltage of our batteries. If that big range isn't possible we could narrow it down from 10-18V. We're flexible with the LED configuration and it's only dependend on the LED driver/controller we could use. One of the most important and not flexible criteria is a high pwm frequency as the lights are supposed to be used for videography(broadcast) otherwise we can go by the available drivers.The output current rrange could be 0.9A-1.2A. series/parallel configuration could be choosen by which IC is available and on it's efficiency

    Best regards,

    Max

  • Hello Max,

    First is to figure out which topology to chose.  The 9V LED can be above 9V according to the datasheet.  A buck converter will not be able to regulate current once Vled gets close to Vin.  If Vin is 10V minimum and the LED was at or below 9V a buck converter can work.  If the LED voltage can be in the range of the input voltage either a boost to battery or SEPIC will be needed.  If the LED voltage is always above the input voltage a boost converter can work.

    The TPS92518 is good for shunt FET dimming at high frequency, it is a dual channel buck converter so this probably won't work depending on Vin and Vled.  The TPS92520 probably won't work due to having a 1.6A current limit.  The TPS92682 has series FET dimming for higher dimming frequencies and can be used as a boost, a boost to battery, or a SEPIC converter.

    Another option is to boost the voltage to a higher voltage rail so a buck converter can be used.

    Best Regards,