A scalable high-performance switched-capacitor filter

Switched-capacitor filters tend to display reduced performance
when implemented at reduced feature size because of higher KT\C
and I/f noise, and reduced operational amplifier gain and swhrg. This
paper describes some circuit solutions to certain performance degradations
associated with technology scalkg, includhg chopper stabilization, and
class AB differential operational amplifier architecture. An experimental
fifth order elliptic PCM low-pass filter, using 3p CMOS technology,
achieved an area of 200 milz per pole. Typical measured results for a
:E 2.5-V power supply are a dynamic range of 87 dB, a power supply
rejection ratio (PSRR) of 40 dB over l-MHz range.