how to decide the gain of error amp in ldo

[manissri]

hi i am desining an ldo
for this i need to decide the gain of error amp
what factor needed to consider to decide the gain of amp.
please give the formula or docs so that i can calculate the gain of error amp for ldo

 

[ashish_chauhan]

Hi

you that ldo has a equation: vout=vref(1+R2/R1).

This assumes an infinite opamp gain... if you have finite gain then... you have some error(difference from ideal value) in output ... which is inversely prop to opamp gain... so depending upon ur tolerence band of regulator output decide the gain...

hope this gives u the basic idea about what to do...