i neeed equivalent component ............

[satya]

hi
i am working on smps power supply

TL431 shunt regulator working up to 37Vdc but i need a shunt voltage regulator working 75Vdc

please give the any equivalent part number.........

[solutions]

I hope you've done the math Vdrop*I - your power dissipation just doubled....

Check out Supertex

[borberk]

Use this:

[tAhm1D]

satya,
You can do it with zener and transistor. For variable ref.,you can add a pot.

[PilotPTK]

You can also add a big 40ish V Zeener before the shunt regulator.  It will eat the 40 Volts and show only 35 to the Shunt regulator.

As solutions mentioned, make sure you have a part that can dissipate 40V * I = Watts.  Running the Shunt Regulator near it's limits also requires watching the VDrop * I for the regulator.

You may want to absorb even more in a zeener if the voltage in is relatively stable..

For example

75V -> 70V Zeener -> Shunt Regulator -> 12V

That way, you can use a big fat zeener, show only 15V to the Shunt Regulator and only have to drop 3V * I in the shunt.

PPtk

[satya]

hi

Thank you
but i need 75Vshunt regulator ( only single component )

i can not use any equivalent circuit.  my pcb  is very small no space available for extra components.


regards
satya

[PilotPTK]

Without additional components, I don't think you're going to get what you need.  The highest shunt regulator that I know of takes a max of 42V IN.

What is your actual VIN and VOUT requirement?  Depending on the drop, something like a floating LM317 might work.

PPtk

[oldvan]

Perhaps you could use a TL783.  Good to 150V input.  Pretty much a LM317 on steroids.
http://focus.ti.com/lit/ds/symlink/tl783.pdf

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=296-20687-5-ND
A couple bucks US each.