• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 64 subscribers
  • Views 113 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LM2753: Configure IC to Drive LEDs in Parallel

Wesley Mandel
Prodigy 30 points
Part Number: LM2753
Other Parts Discussed in Thread: LM36010, LM3644

Hello,

Is there any application information or recommendations to configure this device to drive two LEDs in parallel?

It seems that I could potentially add a second Rflash resistor as depicted in Figure 3 of the datasheet to act as a ballast resistor.

Would this create difficulties for the device's ability to regulate current?

Thank You,

Wesley

  • +1
    TI__Mastermind 19715 points

    Hi Wesley,

    You can view the two LEDs in parallel as a single LED with a different I-V curve. You should design the circuit with this "combined" I-V curve.

    Wesley Mandel said:
    Would this create difficulties for the device's ability to regulate current?

    In fact, LM2753 is a constant-voltage regulator and the output current is set by the current-limiting resistors, R_TORCH and R_FLASH. (Please refer to the Simplified Schematic on the first page of the datasheet.) If you want more consistent and more accurate current regulation, you can take a look at constant-current regulators like LM36010 (single channel) or LM3644 (dual channel).

    Best Regards,

    Steven