Ultra-Low Power Amplifiers for IoT Nodes

In this paper design techniques for operational transconductance amplifiers (OTAs) suitable for IoT applications are analyzed and compared. After a brief review of design techniques exploiting subthreshold (or weak inversion) operation and the body terminal of MOS transistors for signal input or biasing, a comprehensive comparison of the state of the art of fabricated ultra-low-power (ULP) OTAs is carried out. The analysis reveals that subthreshold operation is in perspective the best strategy to implement ULP OTAs for IoT applications.