Switched-capacitor filters tend to display reduced performance when implemented at reduced feature size because of higher

and

noise, and reduced operational amplifier gain and swing. This paper describes some circuit solutions to certain performance degradations associated with technology scaling, including chopper stabilization, and class AB differential operational amplifier architecture. An experimental fifth order elliptic PCM low-pass filter, using 3

CMOS technology, achieved an area of 200

per pole. Typical measured results for a

2.5-V power supply are: a dynamic range of 87 dB, a power supply rejection ratio (PSRR) of 40 dB over 1-MHz range.