Ninth Great Lakes Symposium on VLSI
Linear Transconductors Using Low Voltage Low Power Square-Law Cmos Cells
Ann Arbor, Michigan
March 04-March 06
ISBN: 0-7695-0104-4
Two transconductors composed of two square-law CMOS cells are introduced in this paper. The analysis of the cells is given. The transconductors operate in the saturation region with a fully balanced input signal. Simulations were done for 0.8pm n-well process using BSIM3 model parameters. The first circuit has a trade-off between low voltage operation and low power dissipation. The circuit has a cutoff frequency of 170MHz and Pdis=l.l7mW for a bias current of 120pA. The second transconductor has aimed to overcome the trade-off and to improve the performance; the circuit has a cutoff frequency of 236MHz and Pdis =1.74mW for the same bias current, however, it is possible to reduce the bias current, since the trade-off The transconductors have a THD of less then -56dB and -6OdB, respectively, for lMHz, 0.5V peak-to-peak sinusoidal input. A comparison between the two circuit performances is given.