Find highest value of 4 inputs without microcontroller?

[T3sl4co1l]

Yeah, in the typical case, the pin connects to a sampling capacitor.  The RC time constant plus leakage sets the maximum value for meeting all specifications.  The actual leakage current is small, so the resistance is almost entirely just to ensure analog bandwidth comparable to the maximum sample rate.

Tim

[not1xor1]

just for fun (would need low tolerance or selected parts)

[T3sl4co1l]

^

A perfectly fine application of the TL431, knowing that it is, in fact, an op-amp with a shortage of pins, an open-collector output, and a disturbingly large yet conspicuously stable (2.50V) input offset voltage.

Would also need the high side level translation, and would benefit from a low side CCS, but technically uses fewer pins than the LM324.

Tim

[NiHaoMike]

A perfectly fine application of the TL431, knowing that it is, in fact, an op-amp with a shortage of pins, an open-collector output, and a disturbingly large yet conspicuously stable (2.50V) input offset voltage.

There have been contests around the 555, maybe it's time to have one for the TL431?

[T3sl4co1l]

A perfectly fine application of the TL431, knowing that it is, in fact, an op-amp with a shortage of pins, an open-collector output, and a disturbingly large yet conspicuously stable (2.50V) input offset voltage.

There have been contests around the 555, maybe it's time to have one for the TL431?

Sure.

I want to see one around the UC384x.  I propose that it is as universal, or even more versatile than the 555.

Tim

[not1xor1]

^

A perfectly fine application of the TL431, knowing that it is, in fact, an op-amp with a shortage of pins, an open-collector output, and a disturbingly large yet conspicuously stable (2.50V) input offset voltage.

Would also need the high side level translation, and would benefit from a low side CCS, but technically uses fewer pins than the LM324.

Tim

Probably the LM385-adj would work as well, with ground referenced output and finding the lowest output.