Annotate the device operating points, check your devices are in the saturation region.
How much is the output resistance of your OTA? Are you sure the 100kOhm is high enough to generate DC feedback compared to Rout?
You designed an OTA so if the transconductance is ok you shouldn't worry about the voltage gain. However if the load resistors don't affect the voltage gain, probably your devices will operate in a wrong operating point. Check them.
You designed an OTA so if the transconductance is ok you shouldn't worry about the voltage gain. However if the load resistors don't affect the voltage gain, probably your devices will operate in a wrong operating point. Check them.
Not at all. An amplifier with DC gain below unity would be useless. In this case, the number indicates that you didn't manage to achieve a useful operation point in the test setup.
Not at all. An amplifier with DC gain below unity would be useless. In this case, the number indicates that you didn't manage to achieve a useful operation point in the test setup.
I finally found the problem. Me being the inexperienced designer that I was, simulated the circuit together with the CMFB circuit inside. Which meant I had resistors connecting both my outputs and then was connected to a sense amp. When I simulated separate the OTA and the CMFB, the issue was resolved.
I also modified the testbench based on the testbench from Baker's book. Attached here. Thank you all!
This screenshot is from Baker's CMOS Circuit Design, Layout and Simulation book page 798.