Minimum input voltage for Linkswitch

6 posts / 0 new

The data sheets for the Linkswitch-TN and Linkswitch-TN2 parts shows a minimum Drain pin supply voltage of 50V but the application info seems to indicate that they require a minimum of 70V. I have an application with an input of 60V and output of 5V and I'm trying to understand if I can use these parts.

Hi,
Thanks for using Power Integration products.
By application, the LNK TN and LNK TN2 are guaranteed to operate at above 70V.

Thank you for your reply. However, I'm not sure I understand your answer. The datasheet clearly specifies operation with a minimum drain voltage of 50V for both the LinkSwitch-TN and -TN2 parts. The 70V specification is only listed in the Key Application Considerations section as: "...typical practical continuous output current....under the following assumed conditions:" and under the Quick Design Checklist as "...recommended:".

Please explain: Is the datasheet incorrect in specifying a minimum drain voltage of 50V or does some performance parameter change if operated at a drain voltage of <70V?

Hello wolffdp,

Thank you for interested in using the Link-Switch family product.

70V DC minimum is recommended for the better performance consideration. Here is more considered about the AC input, when you have an AC input and deliver power, you would get some line frequency ripple at the input bulk capacitor. with bigger AC input or the input bulk capacitance, the less line frequency ripple you would get at the bulk capacitor. then the minimum DC voltage at the bulk capacitor would be higher with less AC ripple, here we suggest the DC voltage should be higher than 70VDC. this would help you deliver more power and less output ripple compared to the lower DC input voltage at the bulk capacitor. Moreover, the current table at the front page, table 1: output current table is considered with DC voltage minimum 70V.

Theoretically, your understanding is correct, the link-TN/TN2 can be operated at 60V for you application. But you should not use the table 1 for the device selection as that assumption is for 70V DC minimum. In order for you to check if your design is valid or not, please use our online tool PIxls to do your design check. if no warning is shown in PIxls, i think you should be good to go with the design. i put the link below, you only need to register and can run the web version.

https://piexpertonline.power.com/site/login

Hope this helps.

Best Regards

Thank you. That explanation helps a lot.

Hello wolffdp,

You are most welcome.

Best Regards