• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 387 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

LM3478: Slope compensation

user5860053
Prodigy 30 points
Part Number: LM3478
Other Parts Discussed in Thread: LM5155

The way slope compensation is implemented in fig. 3 of eval board of LM3478 (https://www.ti.com/lit/ug/snva656a/snva656a.pdf?ts=1590694909179) is different than fig. 23 of its datasheet (https://www.ti.com/lit/ds/symlink/lm3478.pdf?ts=1590694227657).

Fig. 3 of eval board shows C_SN cap should be from pin1 (Isen) to GND while fig. 23 of its datasheet shows it should be in parallel with R_sen. Which one is correct? 

  • 0
    TI__Expert 7450 points

    Hi,

    Thanks for your interest in LM3478.

    The Rsl in the eval board is mainly for the RC filter purpose of the current sense signal. It can add a little bit slope but not much.

    The Rsl in the datasheet is usually used for adding enough slope for stability.

    You can refer to LM5155 datasheet https://www.ti.com/lit/gpn/lm5155-q1, 9.3.6 - 9.3.7, which has a better explanation.

    Please let me know if you have any questions.

    Thanks,
    Yinsong