11 GHz UGBW Op-amp with feed-forward compensation technique

A high speed pseudo differential three stage operational amplifier has been implemented using a feed-forward compensation technique in a standard 0.13 μm CMOS technology. The three stage inverter based op-amp with feed-forward compensation achieves 11 GHz of unity gain bandwidth for a nominal power consumption 18 mW, and exhibits 39 dB of DC gain with phase margin of 62° when driving a differential load of (2×300 fF) at a 1.2 V power supply voltage. At a power supply voltage as low as 0.4 V, the same circuit consumes 0.1 mW and achieves 79 MHz of unity gain bandwidth. The proposed op-amp achieves a figure of merit (FOM) [1] of 440 at 1.2 V, and 190 at 0.4 V.