Original question:
TI technical support, hello:
When using TINA-TI to simulate the INA821, there is no problem with the dual power supply, but the transient simulation with a single power supply is aborted, as shown in the figure below. I don't know why? The AC transmission characteristics seem to be wrong?
Best Regards,
William
Hi Wlliam,
the reason for the error is that you violate the common mode input voltage range of INA821. You must stay at least 2V away from the supply rails at the input:
One remedy is to increase V1 from +4V to +5V. Then you wouldn't violate the common mode input voltage range 
Kai
Hi William,
In addition to Kai's comments, we have a Analog Engineer's Tool that can assist you to diagnose the issue. With your single supply voltage rail, Vcm may be configured near the mid supply rail or 2.5Vdc in order to maximize the INA821's output voltage swing, see the image below.
Here is the link to down the tool:
https://www.ti.com/tool/ANALOG-ENGINEER-CALC
If you have additional questions, please let us know.
Best,
Raymond
