Tutorial 13: Analog Circuit Design on Digital CMOS : Why it is difficult, and which ideas help?

This tutorial covers a wide range of small things an analog-IC designer should know to find a path through all the challenges of designing analog circuits on standard digital CMOS processes. The three main topics are: signal integrity (handling noise, treating signal ground, dealing with parasitic modulated feedback in switched circuits) unconventional use of standard parts (exploiting weak inversion, exploiting small dimension effects, unconventional uses of switched-capacitor techniques), and the question whether to feed back or not to feed back (self-biased and regulated current mirrors for gain enhancement, reduction of power consumption with low-feedback circuits.) Most examples come from low-voltage and low-noise broad-band applications, but RF is not covered. Many of the tricks were proven in industrial chips by the author or by people he knows, and will therefore need to be presented without explicit references.