ReRAM write circuit with dynamic uniform and small overshoot compliance current under PVT variations

摘要

Resistive random access memory (ReRAM) is very attractive for dense storage in embedded applications because of its good scalability and logic-process compatibility. However, ReRAM suffers from severe variations in R_off/R_on, endurance and retention, which greatly impair its yield and limit its application. Besides the variation sources from material defects, device non-uniformity and manufacturing deviations, circuit inability to provide an ideal write condition also plays an important role in causing above-mentioned variations. Especially, the requirement for a uniform and small overshoot compliance current during set (forming) is critical for narrowing the low-resistance state (LRS), i.e. R_on distribution, while the prior works fail to satisfy. This paper proposed a write driver with dynamic uniform and small overshoot compliance current under different set/forming voltages. The benefits of self-adaptive write mode (SAWM) are also reserved for both set and reset operations. Simulation shows that the compliance current with 5% variation for PVT variations and 3% overshoot is achieved.