Design of Low Power Linear Multi-band CMOS Gm-C Filter
A continuous-time low-pass reconfigurable Gm-C filter exhibiting a tuning wide bandwidth is presented. The filter uses a wide frequency, linear operational transconductance amplifier (OTA). The operational transconductance amplifier takes an advantage of common mode feed forward (CMFF), two cross-coupling pairs with source degeneration and cascoding topology to realize a low power multi-band filter performance. Based on the proposed idea, a 1st-order low pass Gm-C filter prototype has been designed in 0.18μm standard CMOS process. Simulated results show the filter is tunable in frequency from about 15KHz to 15MHz. The power consumption of the filter ranges from 9uW to 10mW, and it is operated with 3.3V supply voltage. The cut-off frequency of the filter is tuned by changing the dc bias current of the OTA.
Riyas T M, Anusooya S