't hemanth,

Thank you for using our device.

May I ask where do you see this 4.41 of Vds TNY267?I am just curious because typically the value of Vds is around 500 V to 600 V.

The formula of Vds for a typical flyback topology is Maximum DC input voltage + VOR is (reflected The output voltage) + The voltage under caused by The leakage energy.

For TinySwitch device family, the formula of primary inductance can be found in page 45 For continuous conduction mode and page 49 For discontinuous conduction mode in the application note of TinySwitch 3 (The an - 90 _tinyswitch - iii_family_design_guide. PDF (power.com)).

I also noticed that you are using an old version of TinySwitch family, I want to suggest to the latest version of TinySwitch which is the TinySwitch - 4. It has the lower no load power consumption than the old version for example. If you want to check It out, here is the link of the datasheet of TinySwitch4 (Tinyswitch - 4 _family_datasheet. PDF (power.com))

TinySwitch - 4 is also in the PI Expert Online (PI Expert | Power Integrations, Inc.) where the values like the Vds and primary inductance is automatically computed.

Feel free to contact us if you have any further questions.