Title :
A tunable gm-C filter with low variation across process, voltage and temperature
Author :
Khan, Qadeer Ahmad ; Wadhwa, Sanjay Kumar ; Misri, Kulbhushan
Author_Institution :
Semicond. Product Sector, Motorola India Ltd., Gurgaon, India
Abstract :
A tunable gm-C filter with cutoff frequency insensitive to Process, Voltage and Temperature is proposed. An external clock frequency is used to generate a current using a switched capacitor circuit. The proposed filter is ideally suited for applications where a tight control on cutoff frequency is desired across different operating conditions of the chip. The circuit was designed in 3.3 V BiCMOS technology and simulations were carried out using SPICE. The simulation results show that the total variation in the cutoff frequency is 1% as compared to the 27% variation in conventional gm-C filter over the temperature range of -40 to 120 degC. The variation across process corners is 2.4% and is almost independent of the capacitor variation due to process and temperature.
Keywords :
BiCMOS integrated circuits; SPICE; frequency control; operational amplifiers; switched capacitor filters; -40 to 120 degC; 3.3 V; BiCMOS technology; SPICE; bipolar complementary metal oxide semiconductor; capacitor variation; cutoff frequency control; external clock frequency; simulation program with integrated circuit emphasis; switched capacitor circuit; tunable gm-C filter; BiCMOS integrated circuits; Circuit simulation; Clocks; Cutoff frequency; Filters; SPICE; Switched capacitor circuits; Temperature; Tunable circuits and devices; Voltage;
Conference_Titel :
VLSI Design, 2004. Proceedings. 17th International Conference on
Print_ISBN :
0-7695-2072-3
DOI :
10.1109/ICVD.2004.1260975
