LM5118

Hi,
SYNC is an external synchronization clock input. If you don't need to synchronize LM5118 switching with an external clock, SYNC can be left floating.
PGND should be tied to ground.
Regards,
Eric.

Hi,

This schematic build through WEBENCH.

Is this true?

In this schematic Vin pin(first pin of LM5118) directly connect to input voltage (22-35V)!

Please help me.

Please give me the true schematic with true value for these input and output voltage.

Thanks.

I am waiting for response 

I am sorry I have in a hurry.

Hi

LM5118's VIN pin can be directly connected to the power supply input. VIN R-C filter is optional.

Regards,

But when connected directly to the 24V The Lm5118  is hot and output is 0V and I disconnect power supply  fastly.

Hi

Would you please share your schematic ?

Regards,

Hi,

Yes, I attached schematic file.

1145.Schematic Prints.pdf

Hi

Please measure the pin voltages listed below after powering up.

VIN

UVLO

EN

SS

VCC

Regards,

Eric

Hi,

VIN = 24V

UVLO=55MV

EN=10.6V

SS=0V

VCC=1.7V

Hi,

I edit this track from UVLO's pin until Ruv1,Ruv2 and VIN but the voltage of this pin is about 60mv and the LM5118 is hoted.

I forgot to say this subject that I used IRF2807 MOSFET instead AOS7244 and MBR760 diode instead 6cwq06fn.

Thanks.

You say right (24V*2.87k)/39k=about 1.76V but I measured 60mv. I checked all parameter in this track but all of theme is true.

Can you checked my schematic and PCB file in Altium designer that I will send those by e-mail?

Hi,

I find out where is the problem but I don't know why?!

When I disconnected inductor the LM5118 is not hot and the voltage of UVLO = 1.7V.

L= 27.5 μH

the resistance of wire is 60m Ohm.

I am waiting for your response.

Hi,

Please help me.

I assemble and reassemble most of parts but If the inductor or Renable connected to the board Lm5118 is hoted.

I am waiting for response.

I am waiting for response too.

I see you have been waiting for a response. And somehow your thread of your post was marked "Closed'.  Anyway, would you please go to the following webpage and use the Quick Start Calculator?

http://www.ti.com/tool/lm5118quick-calc

Best Regards,

Youhao Xi, Applications Engineering, TI SVA-PPD

Thanks for response, but I used from WEBENCH but the parameter of WEBENCH different the parameter of lm5118quick-calc excel file.

When I started power supply my LM5118 was hoted and when disconnected the inductor the LM5118 has cold but I don't have output voltage.

I want to know my problem relate the PCB or calculation of the parameters that WEBENCH calculated?