International Journal of Computer Applications |
Foundation of Computer Science (FCS), NY, USA |
Volume 177 - Number 23 |
Year of Publication: 2019 |
Authors: Mohammad Reza Safarian, Ghazal Moradi, Saber Izadpanah Toos |
10.5120/ijca2019919671 |
Mohammad Reza Safarian, Ghazal Moradi, Saber Izadpanah Toos . Gain and Bandwidth Enhancement in CMOS Low-Voltage Low-Power Operational Amplifiers. International Journal of Computer Applications. 177, 23 ( Dec 2019), 8-14. DOI=10.5120/ijca2019919671
In this paper, a low-voltage low-power CMOS operational amplifier using the composite cascode technique is presented. This technique has been employed in the differential input pair and output transistors to enhance the gain of op-amp. Also, indirect compensation is used to improve the frequency response of the op-amp and avoids instability when a large capacitive load at the output of the op-amp must be handled. Two-stage op-amp is designed and simulated in a TSMC 0.18 μm CMOS technology, to evaluate the proposed technique. The sub-threshold region is employed in the design to use the low supply voltage and reduce power consumption effectively. The op-amp operates at a 0.7 V power supply with 891 nW power consumption. The open-loop gain is 90.1 dB, the unity gain-bandwidth (UGBW) is 309 kHz, and the phase margin is 57.6 degree under 15 pF load.