Large-Capacitive-Load OTA With NMOS Input and PMOS Input Current Boosting Cells

This paper presents a low-power and high gain-bandwidth (GBW) OTA for large capacitive load applications. The proposed OTA utilizes four differential small-signal current boosting cells to increase DC gain and GBW. In this single stage OTA design, two different small-signal current enhancers with NMOS and PMOS inputs are used. This G
_m
-boosting cells are designed based on the recycling and double-folded structures and have higher current gain with low power consumption. The proposed OTA with 15 nF capacitive load was simulated in a 0.18 μm technology. The simulation results show that the DC gain is 100 dB at the supply voltage of 0.75 V, GBW is 1.42 MHz and phase margin is 57°. The current consumption is 13.35 μA including all bias and common mode feedback circuits.