Part Number: OPA2991
Other Parts Discussed in Thread: TIDA-01527
Hi team,
We were trying to implement the excitation feedback sensing to MCU circuit.and we got a reference circuit of TIDA-01527 Schematic .And we implemented in the simulation ,The output observed is clipped.Can you please confirm the how the expected output should be?
Jayakeerthana P,
The problem you are seeing is the output swing limitation of the op amp. The range of output voltage that an op amp can achieve is limited by its power supplies. Depending on the load current, the output swing can be reduced. Below I show an excerpt of the data sheet that provides details for different loads. Your circuit has about 110k load (Rf + Ri). This is practically the no-load case so you should get close to 10mV from the supply rail. Thus your output could swing from 10mV to 3.29V. The simulation shows clipping at approximately these levels. You can use a cursor in TINA SPICE to see this. Here is a short simple video on the subject: https://www.youtube.com/watch?v=bg1OwZFtOeM .
Best regards, Art
