New active only scaling configuration for grounded passive elements with electronic scaling facility

摘要

This paper proposes a new grounded passive element scaling circuit employing two voltage differencing transconductance amplifiers (VDTAs). The proposed configuration does not need any additional passive element except the element to be scale. So, it can be viewed as a purely active scaling circuit. The presented configuration can scale up/down the value of used passive element which could be a resistor or capacitor or inductor. As scaling factor includes the tranconductance gain terms, the scaling can be done electronically by changing the bias currents of VDTA. The proposed circuit does not require to meet any active/passive component matching condition, enjoys low sensitivity values and good non-ideal behavior. The effect of VDTA terminal parasitics is also investigated on proposed configuration. The workability of proposed scaling circuit has been verified by an application example of voltage mode low-pass filter. To validate the theoretical analysis SPICE simulations with TSMC 0.18μm CMOS process parameters have been performed.