As per LM22680, value of 100uF is recommended as output capacitor.
But, when I try to simulate it using webench tool, there is no option available to select 100uF capacitor and also the limit it says is 50uF maximum for ceramic capacitors.
And for different design it give different value but non of them going to 100uF.
Please clarify
I will pass this along to our Webench guys.
Thanks
Frank D
Hi Velmurugan,
WEBENCH is being less conservative than the datasheet here because it has the specific design requirements. When in the select alternates page for Cout though, if you go to the bottom and create a custom component you can put in any value you want for the cap and use simulation and Opvals to check the functionality.
Best Regards,Tommy JewellWEBENCH Apps
Hi Tommy Jewell
Will it be a problem if we are not going to use the 100uF capacitor. Should we take the web-bench design with out taking care of the information given in the datasheet.
As per my understanding the design that are generated using webbench are bench tested,is this correct?
Regards,
Velmurugan.E
Hi Velmururgan,
WEBENCH is an equation based tool that generates designs on the fly based on the user's requirements and the current database of parts.We do bench validation on test cases, but it would be impractical to test all designs created. We try to provide tools though beyond just a BOM and schematic for you to further validate the design. The Opvals should give you a good idea of the power dissipation and SIM should be able to provide an even more detailed look as to how the part should work.
The AC simulation will be important for your design to verify stability as your choice of output cap will have a big effect on this.
To your first question; yes I would go with the WEBENCH design as a start and utilze the the priveded tools to make sure the design meets your spec.
Regards,Tommy