• State TI Thinks Resolved
  • Locked Locked
  • Replies 2 replies
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 228 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.

LM3281: Effects with output capacitance larger than 9uF

Mark M.
Intellectual 255 points
Part Number: LM3281

On pg 15 of the LM3281 datasheet, it states that total effective output capacitance must be 3.4 μF to 9 μF.

Questions:

  1. Can this part be used with loads larger than 9uF?
  2. What are the issues with output capacitances larger than 9uF? What areas of performance are affected?

  • 0
    TI__Expert 6330 points
    Hi,

    I have notified our expert regarding this topic. Please expect a response by 5/6/19.

    Thanks,
    Aaron
  • 0
    TI__Mastermind 18550 points
    Hello Mark,
    As you noticed in the datasheet, this device is designed and validated for effective output capacitance of between 3.4uF and 9uF. Effective capacitance means accounting for all de-rating factors such as, for example with ceramic capacitors, dc bias, ac bias, aging, temperature etc. Ceramic capacitors are de-rated more than 50% with these factors so a nominal ceramic X7R type capacitor of ~22uF can be used.
    Issues with effective capacitance larger than 9uF are startup problems (converter may not reach target voltage in time due to current limit) and possible loop instability.

    Kind Regards,
    Liaqat