Minimum Voltage for TinySwitch TNY268PN

Posted by: UroBorosTech on 02/12/2014

Hello,

I am new to PI.

Forgive me if I am asking very obvious questions!

Will TNY268 work on 20Volts DC?

Means - can I produce 5V@250ma from 20Volts using this chip?

If not, is 36Volts the minimum value for this chip to work ?

Thanks

Comments

TNY switch are designed for applications with high input voltage, for example 85Vac-265Vac. The MOSFET inside the part is at least 700V, and thus the Rds,on is very high.

I beleive you can find some other parts from companies like TI and maxim for your application. The cost, efficiency and performance should be a lot better than TNY268.

If I were you, I would start from parts of other company.

Regards

Thanks for the inputs.

Actually I have seen a circuit in a device (Schematic attached) where they are producing +5V from 48VDC using this chip.

Looks like a 'hack'. The plan seems different from schemes in the datasheets.

Please suggest a chip using which I can derive +5V from inputs like 12V, 24V, 48V and 72VDC. I can alter the components for each voltage inputs, but PCB should be same.

Regards

UroBorsTech

The schematic is very wierld for me, and I doubt if it works or not! Actually it is more like a linear regulator not a switching mode poqwer supply, and thus the thermal is a big issue even the circuit can really regulate at 5V.

For voltage below 12V, I donot think any PI part can work, because of the maximu duty cycle limit and current limit.

For voltage above 24V, PLS try our DPA family part.

regards

Sorry for the mistake. The schematics I posted was having some istakes.

I correected and attached again.

This circuit works from input of 16 volts and up (input).

Regulation seems ok on a simple multimeter testing.

When loaded with 500ma there is no heat generation.

The inducter can be adjusted to bring volatge to desired level.

Higher currents or other specs like ripple are not tested.

Regards

UroBorsTech