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LP5018: LP5018RSMR

Sampan Shetty
Prodigy 20 points
Part Number: LP5018
Other Parts Discussed in Thread: TLC59116

How to select the value of IREF resistor for the IC for driving 15 LED's.

Forward voltage of led- 3V

forward current- 300 mA

  • 0
    TI__Genius 12915 points

    Hi Sampan,

    Do you mean that every LED on your system need 300mA, or 300mA totally for 15 LEDs. Each channel of LP5018 can only support up to 35mA. 

  • 0 in reply to Hardy Wu
    Prodigy 20 points

    Hi Hardy,

    The led glow will be driven through PWM. Each led has forward current of 300 mA.  So as per my understanding, the resistor is not required as maximum current will not cause led damage? i just wanted to understand the equation given in the datasheet. Will the resistor limit the maximum current across all the leds or limit each individual current of led?

  • 0 in reply to Sampan Shetty
    TI__Genius 12915 points

    Hi Sampan,

    For each channel of LP5018, the maximum current capability is 35mA. Here is protection circuit inside each output channel, which limits the current below around 80mA. But setting resistor above 35mA , it is out of datasheet recommendation and will have potential risk.

    For such high current application, we do not have a single IC can achieve it. You could take a look of TLC59116, which is a 16- channel device and each channel have 120mA capability. Parallel 3 channels together can support up to 360mA. So that 2 pcs of TLC59116 can support your application.