Current mirror
Input: $I_{in}$ and $I_{out}$
Output: $I_{in}$ , possible with gain
Settings:
Notes: For it to work all must be in Regimes > Subthreshold Regime
This circuit consists of a diode connected MOSFET that has a common gate node with another MOSFET of the same type. If both MOSFETS have fixed source voltages and are in saturation, they act as current sources.
They will source the same current if they are the same size and $V_{s_{1}=V_{S_{2}}}$
The input current $I_{in}$ sets $V_{g}$ through the $M_{1}$ diode connection and therefore $I_{out}$.
The output current can be scaled (linearly to the width to length ratio) by choosing different transistor sizes, or (exponentially) by choosing different source potentials $V_{s_{1}}$ and $V_{s_{2}}$
The dependence of the output on the difference in the source potentials is described by (if $M_{2}$ is in saturation):
$I_{out} = e^{(V_{s_{1}}-V_{s_{2}})/U_{T}}I_{in}$
