I am trying to simulate the OPA347 operational amplifier in TINA-TI. There is a basic test circuit in their examples and I am trying to simulate it in order to understand some of the parameters.
It is nothing more than your basic non-inverting configuration utilizing the OPA347. You can see the attached schematic.
An overview:
I have it set up for a gain of 2, 1k load, single supply +5V. My input is 0V DC to start and I expect (ideally) to get 0V out; however, I get 1.854 mV out. The datasheet specifies 2mV of offset typical. There is not minimum and I am content with this result for the most part. The datasheet also says that the output swing voltage can *typically* be 5mV from the rails again there is no minimum specified so that is why I am fairly content with a 1.854 mV output with 0V in.
Now, when I input 1V I expect to see 2.001854 V. 2V because of the gain plus the "original" offset but this is my actual result: 1.99986 (-140 uV). If I input 1.5v I expect to see 3.0001854 V. Again 3V due to the gain and plus the "original" offset but again, this is my result: 3.000008V (8 uV).
I am aware that if you change the gain, your offset will also increase but even with an increasing gain my results do not show the typical 2 mV of offset. It is all measured in uV!
What am I missing? Why is it that when I increase my input voltage my "offset" is in the uV? Why is it no where near what is specified in my datasheet? Any insight would be great.
It is nothing more than your basic non-inverting configuration utilizing the OPA347. You can see the attached schematic.
An overview:
I have it set up for a gain of 2, 1k load, single supply +5V. My input is 0V DC to start and I expect (ideally) to get 0V out; however, I get 1.854 mV out. The datasheet specifies 2mV of offset typical. There is not minimum and I am content with this result for the most part. The datasheet also says that the output swing voltage can *typically* be 5mV from the rails again there is no minimum specified so that is why I am fairly content with a 1.854 mV output with 0V in.
Now, when I input 1V I expect to see 2.001854 V. 2V because of the gain plus the "original" offset but this is my actual result: 1.99986 (-140 uV). If I input 1.5v I expect to see 3.0001854 V. Again 3V due to the gain and plus the "original" offset but again, this is my result: 3.000008V (8 uV).
I am aware that if you change the gain, your offset will also increase but even with an increasing gain my results do not show the typical 2 mV of offset. It is all measured in uV!
What am I missing? Why is it that when I increase my input voltage my "offset" is in the uV? Why is it no where near what is specified in my datasheet? Any insight would be great.
