1.5-V HIGH-PERFORMANCE SC FILTERS IN BICMOS TECHNOLOGY

Line-fed telecommunication circuits like battery-operated circuits must work from very low supplies. Contrary to most battery-operated systems in telecommunication applications, high performance is also required. This paper describes two low-voltage switched-capacitor (SC) filters: one can operate from a minimum supply of 1.5 V and the other from a minimum supply of 2 V (for typical parameter values). Both filters use a fully differential architecture and are fabricated on a standard BiCMOS technology. The lowest supply filter, operated from a 2-V supply, has an SNR of 92 dB and a THD of -70 dB for a 2.4-V(pp) differential signal. Power consumption and area per pole are 60-mu-W and 0.18 mm2, respectively, with a clock frequency of 447 kHz.