high voltage PNP

Wrong decade, wrong technology. Think of another way.

If linearity is not required (ie limiting only) think of amplitude-triggered communication methods. They aresimpler to develop.

RL

legg wrote in news: snipped-for-privacy@4ax.com:

I'm trying to find a bigger transistor to use with the AD8212 High Voltage Current Shunt Monitor. Adding the external transistor buys me a common mode voltage capablility of Vce, totally braindead, but I can't find anything greater than 500V.

Looks like the FMMT560 with 500V is pretty much the end of the rope when it comes to commonly available parts. The IXTH10P60 goes to 600V but it's a (largish and expensive) p-channel FET.

So you need linearity, huh.....?

Try sticking your AD8212 output collector's constant current through the source of a p-channel fet, with the fet gate on the AD8212 'common' terminal. I assume you're getting well-decoupled power from somewhere to run this thing. That should give current info over the fet drain's compliance, if the added capacitance can be suffered at the receiving end.

There are also methods of stringing 'transmitters' in series, with their bases (or gates) on a HV divider. Each collector feeds an emitter (or source) farther down the resistive divider.

Being brain dead isn't something you should be aiming to achieve, despite what your boss tells you.

RL

See a pdf swcadiii model illustrating a sensor using the pnp bipolar string on abse.

RL

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