Standby-Power-Free Integrated Circuits Using MTJ-Based VLSI Computing for IoT Applications

In the next-gen Internet of Things (IoT) era, it is strongly required to construct new computer architectures that consume ultra-low power while maintaining high-performance computing. In the distributed wireless devices network, power-management techniques play important roles to provide the best performance with a limited time-dependent energy source.

However, in the present VLSI based on CMOS, as well as increasing standby power dissipation and PVT variation effects, limit the solutions to the above problems but this paper finds an innovative way for this.

In conventional logic-LSI architecture, logic and memory modules are separately implemented, and these modules are connected to each other through global interconnections. Even if the device feature size is scaled down in accordance with the semiconductor technology roadmap , the global interconnections are not shortened; rather, they are becoming longer, resulting in more delay and higher power dissipation due to interconnections.

Recently, it is known that nonvolatile spintronic devices have advantages such as fast read/write, and high endurance, which offers the possibility of constructing not only stand-alone and embedded RAMs that can be used in conventional VLSI systems, but also “Nonvolatile Logic-in-Memory Architecture” (which are standby-power-free high-performance nonvolatile CMOS logic employing logic-in-memory architecture) There are many advantages of employing spintronic devices, especially magnetic tunnel junction (MTJ) devices with CMOS circuits, Regarding low-power operation, the use of nonvolatility is an efficient approach for power gating. If the power gating is applied in the conventional logic LSI, some standby power can be eliminated but also it has to face some challenges which may discourage application of the power-gating technique.

Fig. 1(a) shows a nonvolatile VLSI processor architecture in which high-density and high-speed MRAMs and nonvolatile flip-flops are used to simply realize nonvolatile logic LSIs. When a part of nonvolatile on-chip memory is merged into logic-circuit modules, as shown in Fig. 1(b), the performance of the nonvolatile logic LSI can be improved. The use of spintronics-device-based nonvolatile logic-in-memory (NV-LIM) architecture not only improves performance but also enhances the reliability of future logic LSIs

As a result, the number of transistors in circuit is more and more reduced in comparison with that of a standard SRAM-based ones.

Still there can be more efficient ways for low power consuming IoT devices which can be invented by adjusting new or altering traditional VLSI component in the IoT network, we just have to keep trying so we can have the IoT era exactly as we dreamt of.

Reference and Image courtesy:-

[1] Takahiro Hanyu, “ Standby-Power-Free Integrated Circuits Using MTJ-Based VLSI Computing for IoT Applications”.