Design of Process-Variation-Resilient Analog Basic Components Using Magnetic-Tunnel-Junction Devices

Masanori Natsui and Takahiro Hanyu

Magnetic-tunnel-junction (MTJ) device-based tunable circuitry is proposed for process-variation-resilient VLSI design. By utilizing the attractive features of MTJ device such as non-volatility and 3D stack ability, post-process-oriented tuning mechanism can be implemented with a small area penalty. Additionally, multiple-valued resistance obtained by series-parallel connections of MTJ devices allows more precise tuning of the operating point in the proposed MTJ-based basic component. The use of the proposed mechanism relaxes the constraints on the design margin, which enables to broaden the variety of circuit topologies available for high-performance, low-power and highly reliable VLSI implementation. An experimental design of a new MTJ-based differential comparator with a parameter-tunable capability shows that the use of the proposed multiple-valued resistance achieves 79.6% reduction of the variation effect for the input-output characteristic. Moreover, a design of a tunable operational trans conductance amplifier (OTA) based on the proposed technique and its performance improvement is also demonstrated.

Keywords: Magnetic tunnel junction device, Circuit conditioning, PVT variation, Post-process variation compensation, Operational conductance amplifier