LNK304 PCB design and components selections help
Hello All,
I have read some topics and documents regarding desiging a low power non isolated power supply using the LNK but still I am a bit confused as I find different designs for the same output voltage. Actually I need a 5v 100mA output.
First:
I am confused how to choose the two input capacitors C1 and C2 which are usually chosen as 4.7 uF, from application note AN-37 it mentioned in page 8 Table 9 that Cin1 , Cin2 > 4uF/Wout. So is 5v * 0.1A = 0.5W ? so it can be less than 4.7 uf ?
Second:
Is there any clear reference for desinging the PCB ? I found several designs. I am really keen to design a safe layout not just any circuit.
Is there any guide regarding design rule checks ? PCB traces width + clearances ?
Thanks.
Comments
Doesn't the LNK304 provide 5v DC ?
Thanks.
Hi Ahmed,
You can design power supply with 5V output by using LNK304.
If you refer to AN-37, Table 9 suggests that use Cin1, Cin2 greater than or equal to 3.3uF (0.25W - 1W) for your output power level.
For Layout guidelines please refer to application example section in the LNK-TN datasheet. Here is the link for LNK-TN datasheet for your reference.
https://ac-dc.power.com/sites/default/files/product-docs/linkswitch-tn_family_datasheet.pdf
Please use PIExpert/PIxls soft ware for your power supply design.
https://ac-dc.power.com/design-support/pi-expert/pi-expert-suite/
Creepage and cleareance distances will depend upon your application. If your designing power supply for an application where it is not accessible end user then if you meet the functional isolation that should be good enough.
Regards,
PI-NANO
Hi Chinnasamy,
This post belongs to someone else. Please post your question as a seperate topic so that someone from PI application group can answer the question.
Regards,
PI-NANO
Sir we are proposed to design SMPS circuit .input :12v/DC to 200V/DC .Output-12V or 15V /DC with 1Amps constant voltage.kindly suggest suitrable IC with related components and circuit daiagram .
Thanking you