High performance reversed nested Miller frequency compensation

This paper presents an enhanced technique to improve frequency compensation in three stages operational transconductance amplifiers (OTA). Based on the reversed nested Miller technique, it uses a current subtractor in the common node of the Miller capacitors, thus significantly improving the gain-band width product (GBW) while ensuring unconditional stability and removing the feed forward path. Also, compared to other existing frequency compensation techniques such as AC boosting compensation or active feedback frequency compensation, the proposed approach exhibits better figure of merits with less power consumption. The simulations of a three-stage OTA with 100 pF capacitive load exhibited 5 pF of total compensation capacitors, 63A degrees phase margin and 4.75 MHz as GBW.