OPA547

How about the old reliable LM675?

Cheers

Phil Hobbs

It is decompensated, only stable at gains >=10. Also no noise specs AT ALL so it is probably even more horrible than OPA547.

Don’t know how you got there. One can use a series RC between the inputs to jack up the noise gain near the unity gain cross. Done properly, that

One gathers that the 547 has degeneration in the input stage to achieve unity-gain stability, which trashes the low-frequency noise as well.

Cheers

Phil Hobbs

can give improved speed with only mildly increased noise.

This might work:

The OPA552 will current limit around 200 mA, and thermal limit to protect itself. I can still fry the 50 ohm output resistor, so I'll hang a thermistor on it and clamp the swing if it gets too hot.

Or let the DPAK resistor heat up the opamp? Use its thermal limit?

Just something I'm playing with.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

What kind of output do you get when you force the differential input to near zero by applying a logic '0' to that inverting XOR?

Nothing shows up searching on T577.

The T577 input is always 3.3v differential. The polarity shifts.

It's a little thing that we make for use in a product. I think we could sell it.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

Can you patch it up with an external Enable or something to duty cycle limit the output in the event of a fault? Seems that would be more convenient than a relatively high power clamp.

How's this look? OPA552 is cheaper.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics