A Review of Integrator Architectures

Conclusions

After a study of various possible architectures we conclude that Gm-grounded-C filters show the most promise for realizing very high frequency continuous time filters in digital CMOS processes. A comparison of the many different transconductor circuits suggests that the differential pair is probably best suited for high frequency work, as long as the linearity requirements are modest. We have also identified the key problems associated with conventional bandwidth programming techniques – dynamic range is the most difficult to maintain at low end frequency settings and frequency response accuracy degrades at high frequencies. An approach to mitigate these problems, that uses optimized multiple switchable unit transconductor cells in parallel, was suggested. This approach will be discussed in detail in the rest of this book.