A 1.2V Wide-Band SC Filters for Wireless Communication Receivers

This paper presents the design of a 1.2 V wide-band switched-capacitor (SC) filter for wireless communication receiver applications. The topology of this filter is the 5th-order elliptic low-pass filter. The highest clock frequency in the system is 50 MHz (effective sampling frequency is 100 MHz with double sampling scheme) while the four programmable cut-off frequencies are 1.25 MHz, 2.5 MHz, 5 MHz and 10 MHz. For low-power systems powered by single-cell battery, the SC filter was elaborately designed to operate at 1.2 V power supply. The double-sampling, 5th-order elliptic SC filter meet the desired -40 dB stop-band attenuation specification. Simulation result show that the 3rd-order input intercept point (IIP3) is about 27dBm. The filter was fabricated in a 0.25mum 1P5M standard CMOS technology and measured frequency responses shows good agreement with the simulation ones. The current consumption is 34 mA from a 1.2 V power supply