ABSTRACT
The basic IoT architecture has various sub-systems such as applications, gateways, processors and sensors. These sub-systems require low power and high speed memories such as SRAM and ROM. The applications of IoT define the type of memory required, i.e., either high speed or low power. Since low-power devices are more in demand, ultra-low-power SRAMs are required for portable and handheld devices. At the same time, the performance of the SRAM should not be degraded. Wearable devices are nowadays the latest trend so these devices require ultra-low-power SRAMs. The need for memory in IoT systems depends on the application. For example, in applications where a vast amount of data storage and handling is required, the memory requirement switches to DRAM and flash memories. The applications that require a high data transfer rate need fast SRAM memory. High-speed data transfer is essential for communication between IoT devices. So, SRAM is chosen as a cache memory due to its faster response. FinFET-based SRAMs are successful in various applications and are being used nowadays in most of the mobile phones and many IoT devices. Similarly, CNTFET- and TFET-based SRAMs have also been proposed, and in future, we may expect their production. This chapter deals with various design issues of SRAMs from CMOS to various nano-scale devices and their advantages and limitations to their design and applications.
