Low-power Bulk-driven Subthreshold OTA and CCII+ Cells based Instrumentation Amplifier for LF Applications

Abstract

This paper at onset describes a low-power, bulk-driven, folded cascode (FC-OTA) and second generation positive current conveyor (CCII+) operating in weak inversion region with ± 0.35 V DC bias supply. The designed 2 or 3 numbers of CCII+ cells are utilized to compose an instrumentation amplifier (IA), which dissipates a total power of 3.847 µW or 5.768 µW. The OTA cell as the input core in CCII+ circuitry consumes a power of 287 nW, whereas the CCII+ cell consumes total power of 1918 nW. The CCII+ cell uses an OTA which is followed by two-CMOS class AB inverters to realize the X and Z terminals of CCII+ cell. Further, these CCII+ cells are utilized to get low power IA usable in analog front ends of DSP processor for amplifying sensed signal with very high-common mode rejection ratio (CMRR) and high-power supply rejection ratio (PSRR). This IA is simulated using tanner EDA tool of version 16.1 in 180 nm n-tub standard CMOS process technology. This IA consumes less power and is usable as variable gain amplifier for low- frequency bio-signal as well as sub-audio frequency range signal processing.