LM5002: LM5002 SEPIC with coupled inductors

Hitesh Barot

Part Number: LM5002

Hello Guys,

I would like to use a LM5002 for a 10-36 VDC in with 16VDC out @ 150mA. I have used the same schematic given in the datasheet for 24 VDC SEPIC regulator ( made change the value of resistors for Feedback R5= 11.8K and R6 =1K). and changed the EN pin resistors for min value of 10 V ( R1= 17.5K and R2 = 2.49K). Also getting the 16 V output but as i put the load at output of more than 10mA the voltage is getting down .

Can you guys pls help me out for this possible issue or share some design calculation regarding the same? Also see the attached schematic.

Thanks in Advance !

Regards,

Hitesh

over 6 years ago

0 Youhao Xi over 6 years ago

TI__Guru 68595 points

It looks like your coupled inductor polarity is wrong. If the dotted end of L1 is on the right side, then the dotted end of L2 should be on the high side.

Thanks,
Youhao Xi, System and Applications Engineering, APP-BMC-BCS, TI

0 Hitesh Barot over 6 years ago in reply to Youhao Xi

Prodigy 110 points

Hi Youhao,

Yes, you were right , the polarity of coupled inductor was not matching, after changing it working .

Thanking You,

Regards,

Hitesh

0 Youhao Xi over 6 years ago in reply to Hitesh Barot

TI__Guru 68595 points

We really appreciate your feedback and confirmation. Please let us know if we can be further assistance. Thanks!!

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LM5002: LM5002 SEPIC with coupled inductors