Spin-orbit torque flash analog-to-digital converter

TY - JOUR

T1 - Spin-orbit torque flash analog-to-digital converter

AU - Ghanatian, Hamdam

AU - Benetti, Luana

AU - Anacleto, Pedro

AU - Böhnert, Tim

AU - Farkhani, Hooman

AU - Ferreira, Ricardo

AU - Moradi, Farshad

PY - 2023/6

Y1 - 2023/6

N2 - Although analog-to-digital converters (ADCs) are critical components in mixed-signal integrated circuits (IC), their performance has not been improved significantly over the last decade. To achieve a radical improvement (compact, low power and reliable ADCs), spintronics can be considered as a proper candidate due to its compatibility with CMOS and wide applications in storage, neuromorphic computing, and so on. In this paper, a proof-of-concept of a 3-bit spin-CMOS Flash ADC using in-plane-anisotropy magnetic tunnel junctions (i-MTJs) with spin-orbit torque (SOT) switching mechanism is designed, fabricated and characterized. In this ADC, each MTJ plays the role of a comparator whose threshold is set by the engineering of the heavy metal (HM) width. Such an approach can reduce the ADC footprint. Monte-Carlo simulations based on the experimental measurements show the process variations/mismatch limits the accuracy of the proposed ADC to 2 bits. Moreover, the maximum differential nonlinearity (DNL) and integral nonlinearity (INL) are 0.739 LSB (least significant bit) and 0.7319 LSB, respectively.

AB - Although analog-to-digital converters (ADCs) are critical components in mixed-signal integrated circuits (IC), their performance has not been improved significantly over the last decade. To achieve a radical improvement (compact, low power and reliable ADCs), spintronics can be considered as a proper candidate due to its compatibility with CMOS and wide applications in storage, neuromorphic computing, and so on. In this paper, a proof-of-concept of a 3-bit spin-CMOS Flash ADC using in-plane-anisotropy magnetic tunnel junctions (i-MTJs) with spin-orbit torque (SOT) switching mechanism is designed, fabricated and characterized. In this ADC, each MTJ plays the role of a comparator whose threshold is set by the engineering of the heavy metal (HM) width. Such an approach can reduce the ADC footprint. Monte-Carlo simulations based on the experimental measurements show the process variations/mismatch limits the accuracy of the proposed ADC to 2 bits. Moreover, the maximum differential nonlinearity (DNL) and integral nonlinearity (INL) are 0.739 LSB (least significant bit) and 0.7319 LSB, respectively.

UR - http://www.scopus.com/inward/record.url?scp=85161655587&partnerID=8YFLogxK

U2 - 10.1038/s41598-023-35845-7

DO - 10.1038/s41598-023-35845-7

M3 - Journal article

C2 - 37296130

AN - SCOPUS:85161655587

SN - 2045-2322

VL - 13

JO - Scientific Reports

JF - Scientific Reports

IS - 1

M1 - 9416

ER -