Do you mean an amplifier which has a negative power supply?
The input signal is referenced to 0V ground.
Sensitivity is greatest when you use a P-device, and connect it directly to 0V ground. That is, the terminal which corresponds to a transistor emitter.
The simulation shows current flowing from 0V to -12V.
Actually, I have to design this circuit.
This is the Analog counterpart of a metastable latch.
So, there's a negative amplifier...I want to design that using CMOS in Tanner (S-EDIT).
An Common Source Amplifier is an Inverting Amplifier.
Isn't this just a Flip Flop? just use some fixed Capacitors/Resistors to control the value of C and R without having to depend on the intrinsic caps and impedance.