Resistively compensated and SSF based VDBA offering high GBW and its application as a biquad filter

Abstract

This paper presents a new CMOS realization of voltage differencing buffered amplifier (VDBA). The input stage of VDBA is resistively compensated and output stage is a super source follower (SSF). The resistive compensation enhances gain bandwidth product (GBW) and buffer stage improves phase margin and linearity of the active element. The performance of the proposed block has been verified by using Mentor Graphics Eldo simulation tool with TSMC CMOS 0.18 µm process parameters. A new biquad filter is also realized using single VDBA. The three standard filter functions like band pass, high pass and low pass can be realized without changing the circuit topology. All applications are verified with their simulation results. The circuit of SSF based VDBA is quite small and compact. The ac simulation results of complete VDBA show that GBW is 950 MHz and power consumption is 0.45 mW.