PCB Layout review of auxillary supply

[sabu31]

Dear All,

I am making a DC-DC Converter for auxiliary power supply application. The input is 40-58V. The outputs are 18V,0.3A and 12V,1.5A. The initial design I got through PI designer, Based on available components, I made few changes. Can you please review the layout if its acceptable both functionally and as per general safety/emi requirements. Also if any improvements need to be done regarding schematic design aesthetics.

Thanks

 

[KlausST]

Hi,

Why is the switcher IC type a secret?
Also other parts like the optocoupler ...
Basically we see just resistor values... Not sufficient to say whether the design is good or not.

I can only recommend to provide COMPLETE informations ... as well as links to datasheets.
I also recommend to go through application notes and design notes that usually the semiconductor manufacturers provide.

Do you need it to be isolated? Why? What isolation voltage?

Klaus

 

[sabu31]

HI Klaus,

I am sorry , i forgot to include the switcher name. I am attaching the updated schematic and also the reference schematic.

a) I want to know if SMD capacitor is sufficient for snubber or there are any specific material type to be used for snubber.

Also I have included some test points as this is first prototype being made. This is not for industry production, but as an inhous aux supply.
However, later on may be larger prototypes will be made.

The application is for low voltage systems, the maximum input voltage is 60V. So isolation may be required may be for 100V.

b) Should I isolation be higher or any other test points to be included.
c) Do you think the switching loop area is small enough.

Thanks & regards,

 

[cupoftea]

SMD is ok for primary clamp/snubber, but why dont you do it more like the PI schem? ie, a proper RCD clamp.
Cant see layout so cant speak of loop area.

--- Updated Jul 28, 2024 ---

sim an equivalent of it in LTspice and see how it goes...heres one you can adapt