Tool/software:
Dears,
This op amp bias is so small. Why is the output of 3mv when the 3 PIN is 0? When the voltage is 0.8V, there is basically no difference. It shows that it is not the overall lifting 3mV. It is mainly used to reduce it by subsequently, why is this?
Best Regards,
Arabella Zhang
Arabella,
Only input of rail-to-rail op amps can swing all the way to its supplies BUT output can never swing all the way to its rail (GND). In case of OPA333 its output is specified to get within 30 mV above negative rail so 3 mV is much better than what the data-sheet specifies (see below).
No, the output swing to the rail will NOT improve by changing RL to 1k and if anything may only get worse. As i said before, output may never swing all the way to its rail (GND). This is because the output swing to the rail is a function of quiescent current of the output stage (IQo) and Ron resistance of the output transistor - see below.
