LM3481: LM3481 SPEIC circuit review

Hi Sunny,

Thank you for posting.  There is an LM3481 SEPIC evaluation board and you and your customer can check against that example circuit (AN-2094: https://www.ti.com/lit/ug/snva461a/snva461a.pdf)

The customer's schematic has an obvious error:  C9C is placed at a wrong place.  It should be placed between the ISEN pin and AGND.   Please also refer to that said evm schematic to follow the example of separating AGND and PGND signals.  There should be single point connection between AGND and PGND to prevent the switching noise on PGND from affecting the control circuit which references to AGND. 

Thanks,

Youhao Xi, Applications Engineering