Programmable Voltage Reference TL431IZT , what does it do?

Thanks Chris, I think I'm getting it now how it works

It amplifies the error between the internal reference voltage and the voltage at the REF pin.

Click to expand...

So the TL431 is a comparator/amplifier combo much like a regulator , The internal reference voltage is 2.4 volts and it compares it with the external REF pin voltage to either compensate or make up for the loss or to adjust the voltage back down to MATCH the internal reference voltage that is inside the TL431 chip

What the TL431 is going it is MATCHING the REF pin with the Internal reference voltage so it is MATCHING at all time

Is this correct?

You are thinking now Billy....

Great stuff. Not that hard is it ???