A novel high-swing high-speed with 187 µW power consumption Common-Mode Feedback Block (CMFB) based on rail-to-rail technique

This paper presents a new high-swing, high-speed and low power continuous-time Common-Mode Feedback Block (CMFB) based on rail-to-rail technique. The main purposes of the proposed idea are to achieve high-speed, low settling time error, large output swing, and low power as well. Moreover, applying the worst case simulation (initial condition 0 and 1.8 volts) on the proposed CMFB circuit, the output voltage can be settled in the desired level just after 1.18ns noticeably. The settling time error and the power consumption of the suggested common-mode feedback circuit are just 103|iV and 187µW with the power supply of 1.8 volts respectively. Meanwhile, DC gain and phase margin of the amplifier are 74dB and 67 degree correspondingly, and 0.5pF capacitor load is applied to the output nodes of the amplifier. It is noteworthy that, the proposed idea is a good candidate for low voltage applications too. Because it just needs 2 overdrive voltage (AV) to start its performance. Applying the proposed idea on the folded cascode amplifier it achieves SNDR of 68.68dB with the Effective Number of Bits (ENOB) 11.15 bits respectively. The proposed CMFB occupies an active area of 155.58µm² (10.56µm*14.73µm). Finally, the proposed structure is simulated in whole process corner condition and different temperatures from -70°C to +70°C. Simulation results are performed using the HSPICE BSIM3 model of a 0.18µm CMOS technology.