Thank you , I think my problem was due to something wrong with my chip or my pcb. I just made the circuit on breadboard with a new chip it seems like working nice.
Are you talking about Output Current Source value written in the datasheet when you are implying >20mA . Also In other circuit I am using 2.25 volts as buffer again and in the output of the OPAMP I have a 5K potentiometer to create a reference voltage between 0 and 2.5 volts for my microcontroller ADC . But When I drive 2.25 volts through buffer my ADC reference voltage changes between 0.3 and 1.8V while I was trying adjust with pot. ? Is there any way to make this work between zero and 2.25 volts ?
Understanding the datasheet values are really hard for me , do you know any wiki source or something about this issue ?
FvM, Thank you very much for your glance at my circuit !!