Design of a Low Voltage Analog-to-Digital Converter using Voltage Controlled Stochastic Switching of Low Barrier Nanomagnets

TL;DR

This paper proposes a novel low-voltage ADC design using voltage-controlled stochastic switching of superparamagnetic nanomagnets, eliminating the need for comparators and enabling energy-efficient, compact sensor applications.

Contribution

It introduces a new ADC architecture leveraging voltage-controlled stochastic nanomagnet switching, demonstrating its potential for low-power, comparator-free analog-to-digital conversion.

Findings

Stochastic switching characteristics analyzed through simulations.

Voltage bias influences switching behavior significantly.

Proposed device achieves low-voltage 8-bit ADC without comparators.

Abstract

The inherent stochasticity in many nano-scale devices makes them prospective candidates for low-power computations. Such devices have been demonstrated to exhibit probabilistic switching between two stable states to achieve stochastic behavior. Recently, superparamagnetic nanomagnets (having low energy barrier EB $\sim$ 1kT) have shown promise of achieving stochastic switching at GHz rates, with very low currents. On the other hand, voltage-controlled switching of nanomagnets through the Magneto-electric (ME) effect has shown further improvements in energy efficiency. In this simulation paper, we first analyze the stochastic switching characteristics of such super-paramagnetic nanomagnets in a voltage-controlled spintronic device. We study the influence of external bias on the switching behavior. Subsequently, we show that our proposed device leverages the voltage controlled stochasticity in performing low-voltage 8-bit analog to digital conversions. This eliminates the need for comparators, unlike the Complementary Metal-Oxide Semiconductor (CMOS)-based flash Analog-to-Digital converters (ADC). This device allows for a simple and compact design which can potentially be applied in implementing sensors which desire low voltage conversions.