A 5th order Butterworth gm-C Low pass filter design based on the enhanced gm/ID methodology

An enhanced gm/I_D methodology is presented. Two more design parameters are added to the original method. It is demonstrated by examples to illustrate the enhancement of the gm/I_D method which is suitable for low voltage and low power design. A fifth order Butterworth Gm-C low pass filter with automatic frequency tuning circuit is designed using the enhanced gm/I_D methodology. The simulation results show that the design of the low pass filter based on the optimized method achieves the given specifications very well.