Variable-gain amplifier for ultra-low voltage applications in 130nm CMOS technology

The paper deals with design and analysis of a variable-gain amplifier (VGA) working with a very low supply voltage, which is targeted for low-power applications. The proposed amplifier was designed using the bulk-driven approach, which is suitable for ultra-low voltage circuits. Since the power supply voltage is less than 0.6 V, there is no risk of latchup that is usually the main drawback of bulk-driven topologies. The proposed VGA was designed in 130 nm CMOS technology with the supply voltage of 0.4 V. The achieved results indicate that gain of the designed VGA can be varied from 0 dB to 18 dB. Therefore, it can be effectively used in the many applications such as automatic gain control loop with ultra-low value of supply voltage, where the dynamic range is the important parameter.