A Mixed-Signal Short-Term Plasticity Implementation for a Current-Controlled Memristive Synapse

Short-term plasticity (STP) is a synaptic modification process found in biological synapses that increases the computational power of the neuronal network. To implement plasticity rules, we use a memristor-based synapse due to its inherent plasticity. The synapse is designed to operate in the low resistance state (LRS) region using a current-controlled mechanism to account for the device non-idealities encountered at the high resistance state (HRS). In this work, we implement a mixed-signal STP circuit for this synapse design. The STP circuit uses a digital part to generate pulses to initiate the weight change, and an analog part to update the programming voltage. The STP functionality is verified using a 65 nm CMOS process, and the performance metrics are reported. Results show that our circuit achieves a great performance in terms of area and power consumption.