Larry_80 wrote on Jun 1st, 2015, 6:33pm:Hi,
I am just wondering if anyone can comment on challenges faced in making a relatively high quality active inductor in the 16nm finfet process node? From what i heard it is tough to make considering large area and the variation associated with the design. Please kindly comment on challenges you have encountered and how you have been able to overcome them.
LE -- it is Gyrator ( RC LPF at the input is seen as HPF).
Larry_80 --
Pros:
1. Better than Resistance. The source degeneration with resistive load is 2 pole one zero system. Replacing resistive load with active inductor makes it 3 poles and 2 zeros system. This improves peaking and adds linearity to overall gain function.
Cons:
1. Noise of active inductor is higher ( noise folding) and may go beyond overall rms noise spec
2. Unlike simple resistance, maintaining the common mode is challenging but use of replica bias might help.
Thanks
-Bharat