Hi SZ,

Thank you for using E2E forums, regarding your query there are no simulations or any reference design where LM51521 is used as a SEPIC. LM5152 and LM51521 are same device the only difference being the bypass operation. May I ask why are you not going for other devices that can be used as SEPIC such as LM515X family or LM5122?

BR.

Haroon

Thank you for your reply. The LM5152x-Q1 offers forced PWM mode which is important for us regarding EMC. Moreover, the switching frequency should be >2Mhz.

Best regards

SZ

Hi SZ,

I think LM5122 also has the FPWM mode and the switching frequency provided by the LM51521 is also not above 2Mhz.

BR,

Haroon

LM51521-Q1 up to 2.2MHz

Hi SZ, 

Apologies, I thought you meant above 2.2 MHz, in any case LM51521 has not been used for SEPIC. May I know the end application and other design spec requirements?

BR,

Haroon

Hi Haroon,

thank you for your reply. The specs are:

f_sw>2 MHz

Imax=70mA

Vout=15V

Vin_ 8.5V...33V

fixed f_sw-> FPWM

best regards

SZ

Hi SZ,

I found this reference design with similar specs https://www.ti.com/tool/PMP31139 , but it is with the LM515X family device. I would go for one of the LM515X or LM5122 for SEPIC as there are SEPIC reference designs done with those devices.

There is also this older device of LM5022 that can be used as well, but as I said, I will recommend the one I mentioned above.

I hope this helps.

BR,

Haroon