What is the variation expected in Current mirror(Simple Current Mirror) due to MOSFET mismatch? what are the other parameters that can affect the accuracy?
For example if a current mirror is designed for 10mA. How much is variation expected due to MOSFET mismatch?
Re: variation expected in Current mirror due to MOSFET mismatch
If the MOSFETs are in an IC then it entirely depends upon how closely the devices are matched in the IC fabrication process being used.
If the MOSFETs are separate discrete devices than the match could be quite poor, since it depends upon the difference in threshold voltage (Vth) between the two, and that can be quite large.
If the MOSFETs are in an IC then it entirely depends upon how closely the devices are matched in the IC fabrication process being used.
If the MOSFETs are separate discrete devices than the match could be quite poor, since it depends upon the difference in threshold voltage (Vth) between the two, and that can be quite large.
Re: variation expected in Current mirror due to MOSFET mismatch
Wilson CM is the best CM rather than others, in term of accuracy. The mismatch can be due to w/l ratios, threshold voltage, channel length modulation, etc.
To find the mismatch you can simply use simulator software, e.g. Hspice, simulate the circuit and then see the .netlist.