Part Number: LM27402
Tool/software: WEBENCH® Design Tools
Hi,We are using the "LM27402" buck controller for converting Vin=3.3V to Vout=1V@10A. For this design, we need a soft start delay tss=5ms. For this delay, the WEBENCH is recommending to use a capacitor of Css=47nF. But as per the formula mentioned in the datasheet of "LM27402" if we substitute the value of Css=47nF,tss=Css*0.6/Iss,=> tss= 47nF*0.6/3uA,=> tss= 9.4ms
So, can you please suggest which one is reliable. Our requirement is we need a soft start delay tss=5ms, can we take the WEBENCH simulation report capacitor value or we need to calculate it as per the datasheet. ?
Thanks for reporting this issue.We are working to fix the Webench equation.We shall keep you updated on the same.
We are glad that we were able to resolve this issue, and will now proceed to close this thread.
If you have further questions related to this thread, you may click "Ask a related question" below. The newly created question will be automatically linked to this question.
In reply to Umayal Ramanathan:
We have fixed this issue.The fix will be tentatively available on ti.com by 21st September.
Will let you know once the fix is available on ti.com.
For your immediate reference, please find attached WEBENCH design report for your condition. Kindly let us know in case of any queries.
Thanks and Regards,
The fix is now available on ti.com. Kindly let us know in case you have any queries.
Thanks & Regards,
All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs andembedded processors, along with software, tools and the industry’s largest sales/support staff.