Hi
I would like to know how to decide the condition of "Large signal voltage gain".
For example, AD8542's condition is
Vs=2.7V VCM=1.35V
RL=100Kohm Vo=0.5 to 2.2V
Vs=5V VCM=2.5V
How to decide this vo condition?
Why 0.5? Why 2.2V?
Other case, OP295's condition is
RL=10Kohm 0.005V<= Vout <= 4.0V
Vs=+/-15V
RL=10Kohm no output voltage description.
in this case why 0.005V? Why 4.0V?
In AD8542 case, Vs=5.0V, 3.0V's vo conditions are same as Vs=2.7V.It means to cut the test ? and Avo does not depend on Vs voltage?
For example, condition is Vo= 0.1V to 2.5V,then how much the Avo will degrade?
In OP295's case, why vo is very low?
I would like to know the concept of vo decision.
Regards
moto
Hi, moto.
Avo depends on supply voltage but the AD8542 does not follow this. I don't know why. Usually, for the newer datasheets, the Vo is set to be between 0.5V to 1.5V away from the rails in order to have a better Avo value and this Vo depends on Vsy.
For the OP295, the Vo range was chosen because it is the range that gives a good Avo number.
Hope this helps.
Regards,
Anna
Dear Anna
Thank you very much for your help.
It might depend on the designer's idea.
But they select the setting that gives a good Avo number.
I see.