• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 70 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.

LM63615-Q1: Recommended external components value

Kento Adachi
Expert 3315 points
Part Number: LM63615-Q1

Tool/software:

Hello experts,

In table 8-1 and 8-2 in the datasheet, we can find the recommended component values for the internal compensation optimization.

As you know inductor value will decrease with increse of current and cap value decrease with DC bias. Then, do these recommended values correspond to the values at 0A, 0V, room temp characteristic? or should these value include inductance/capacitance change with current/voltage/temp?

For example, 2.5A output 400kHz, Vout=3.3V case, recommended L and C are 6.8uH and 3x22uF. Are 6.8uH and 3x22uF the values at 2.5A and Vout=3.3V? or Are 6.8uH and 3x22uF the values at 0A and no DC bias?

Thanks,

Kento

  • 0
    TI__Mastermind 18525 points

    Hi Kento,

    These recommendations reflect the effective inductance and capacitances and meant to be taken as 6.8 uH at 2.5 A or 66 uF at 3.3 V. 

    There is some leeway as always, but our general recommendation is for capacitors to be rated for at least 2x the voltages they are set to experience. This allows the capacitors to avoid significant de-rating under DC bias.

    For inductors, it is important to look through the inductor manufacturer's saturation curves to ensure that the inductor's current rating is sufficient under the device's most strenuous loads. The is the high side current limit rating that is detailed in the 6.4 EC table of the datasheet is the limit that we recommend the inductor be evaluated against. Please see section 8.2.2.3 of the datasheet for more details.

    Thank you,

    Joshua Austria