Hi:

Thanks for contacting PI. You can try to use out latest Top switch IC, JX or HX. There is no problem to get start up time less than 50ms.

Please refer to the design example: http://www.powerint.com/sites/default/files/PDFFiles/rdr242.pdf

Or: http://www.powerint.com/sites/default/files/PDFFiles/rdr142.pdf

You can also use LNK HP ICs at this power range, it can elimate the feed back optocoupler for the power supply. Please refer to the design example: http://www.powerint.com/sites/default/files/PDFFiles/rdr313.pdf

Thanks

Thanks for response
Unfortunately all present designs use transformer and I need a circuit without him.
Can I convert these designs in transformerless?

Hi.

Yes, you can design a buck (transformerless) using top switch. I found a Design Idea for your reference:

http://www.powerint.com/sites/default/files/di1.pdf

Hi

Thanks again

This desing for TOP222 IC which has big auto-restart time for me (1.2 Hz). TopSwitch-JX and TopSwitch-HX is better than TOP222 but have you some desings for transormerless circuit with these family devices?

And other question. TOPSwitch-II family is pin-to-pin compatible with TOPSwitch family and so I can easy convert my project to low voltage input, for example 42V. Have TopSwitch-JX and TopSwitch-HX similar pin-to-pin compatible with familiy for low voltage input?

Best regards

Hi

Yes, I would definitely recommand you to use our latest Top Switch products HX and JX. The idea will be very similar to the design reference for TOP222.

For HX and JX, they have different packages, the E package is availabe for both ICs. So if you use this package, they will be pin to pin compatible.

Thanks

I'll try to design the power supply with TOP254.
The last question. Is it possible to use this family for AC/DC devices with 42 V input voltage?

Yes, it can be used with 42V input voltage too by proper design.  

Great

Thank you very much. I'll try it

Hi,

I have requirement for transformer less power supply for input voltage 85 VAC- 265 VAC & output 24 V at 1 A. Please suggest

Thanks

Hi Ketan,

Thank you for your inquiry. What is your application? Is it for LED lighting with constant current output?

Best Regards,
PI-SevenofNine

Hi,

It is for HVAC equipment controllers.

Regars
Ketan Gupta

Hi Ketan,

You can try to use our TopSwitch product configured as BUCK. You may refer to the link below for the literature. Thank you.

https://www.power.com/sites/default/files/forum/files/top%20switch%20Buckconverter.pdf

Best Regards,
PI-SevenofNine