Design of Class-AB Level Shifted Flipped Voltage Follower Cell

Abstract

The low-voltage/low-power techniques are used as an integral part of the design process for any modern electronic device. To achieve downscaled supply voltage and a resultant low-power operation, an extensive research of such techniques is required. Flipped voltage follower (FVF) is an analog cell that can operate under low supply voltage environment and consumes less power and can be used for designing the analog circuits. With the advantages offered by it, it has presented itself as a promising substitute of other conventional low-voltage/low-power techniques. The research work includes designing of class-AB level shifted flipped voltage follower (LSVFVF). The level shifter is used to increase the swing of flipped voltage follower. In the proposed circuit bulk-driven MOSFET is used as a current source which improves the sourcing capability and symmetrical slew rate for class-AB operation. The circuit has input/output swing of 1.01 V/0.809 V, wide bandwidth of 750.92 MHz and low output resistance of 106.78 Ω. The applications of the proposed circuit as current sensing cell and differential structure using LSVFVF cell are also presented. The proposed circuits have been designed and simulated in CadenceVirtuoso Analog Design Environment using BSIM3V3 180 nm CMOS technology. The comparison of the proposed LSVFVF with flipped voltage follower cells available in literature shows that the proposed LSVFVF can be used in designing of analog circuits.