AN57 includes "K(TL431)" factor
Posted by: treez
on
Hi,
Why does AN57 include the open loop gain of the TL431 in the feedback equation, whereas AND8334 from onsemi does not include it? (AND8334 page 5)
Hi,
Why does AN57 include the open loop gain of the TL431 in the feedback equation, whereas AND8334 from onsemi does not include it? (AND8334 page 5)
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The TL431 is a rather poor excuse for an opamp, with an open loop gain of only around 55-60dB., therefore, the error term will be larger than with a "real" opamp, hence the inclusion of the open loop gain in equation 23.