A Fast Adaptive and Fine Stabilizer Based Digital LDO

Ibrar Ali Wahla; Muhammad Abrar Akram; In-Chul Hwang

doi:10.23075/jicas.2025.11.2.009

Ibrar Ali Wahla Kangwon National University https://orcid.org/0009-0000-7526-7031
Muhammad Abrar Akram Qatar University, Doha, Qatar https://orcid.org/0000-0001-7574-8695
In-Chul Hwang Department of Electrical and Electronics Engineering, Kangwon National University, Chuncheon, South Korea https://orcid.org/0000-0002-0045-9984

DOI: https://doi.org/10.23075/jicas.2025.11.2.009

Keywords: Digital Low-Dropout Regulator, Fine Voltage Stabilizer, Fast Adaptive coarse controller, Glitch driven control

Abstract

In this brief, fully integrated digital low-dropout regulator (DLDO) is proposed to address the trade-offs between transient response and power efficiency in dynamic load conditions. The design features a fast-adaptive glitch-driven coarse loop controller, which rapidly adjusts PMOS switches using precisely generated pulses, minimizing transient recovery time (T_REC) even during large load current (I_LOAD) changes. Additionally, a fine voltage stabilizer ensures steady-state voltage stability by employing high-resolution PMOS control. The DLDO is fabricated in a 65-nm CMOS process, the proposed DLDO supports an input voltage range of 0.6 V to 1.2 V and achieves a regulated output voltage from 0.55 V to 1.15 V. Simulation results demonstrate a 264 mV voltage droop recovery within 19.11 ns for a 26 mA load step, achieving a figure-of-merit of 0.225 ns² and a peak current efficiency of 99.32%. The low quiescent current of 157 μA makes it highly suitable for power-efficient SoC applications requiring both fast transient response and precise voltage regulation.

Author Biographies

Ibrar Ali Wahla, Kangwon National University

IBRAR ALI WAHLA received the B.E. degree in electronics engineering from Pakistan Air-Force Karachi Institute of Engineering and Technology (PAF-KIET), Karachi, Pakistan, in 2016, and the M.S. degree in electronics engineering from Hallym University, Chuncheon, South Korea, in 2021. He is currently pursuing the Ph.D. degree in electrical and medical convergent engineering with Kangwon National University, South Korea.
His research interests include analog and mixed-signal CMOS integrated circuits, embedded systems, digital integrated circuit design, and power management. His work has primarily focused on developing advanced
solutions for efficient energy utilization and miniaturization of circuitry in power management.

Muhammad Abrar Akram, Qatar University, Doha, Qatar

MUHAMMAD ABRAR AKRAM (Member, IEEE) received the B.S. degree in electrical engineering from the University of Punjab, Lahore, Pakistan, in 2013, and the combined M.S. and Ph.D. degree in electrical and medical convergent engineering from Kangwon National University, Chuncheon, South Korea, in 2019.
From 2019 to 2023, he was a Postdoctoral Associate with the Engineering Division, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates, where he extensively worked on the sensing-interface circuits. After a rewarding Postdoctoral tenure, he joined the Department of Electrical Engineering, Qatar University, Doha, Qatar, in 2024, as an Assistant Professor. His research interests include analog/mixed-signal CMOS integrated circuits for power management in system-on-chip devices, wireless-powered mm-scaled biomedical implants, and sensing interface circuits.
Dr. Akram received the President Award and Company Special Award from Korean Semiconductor Industry Association (KSIA), South Korea, in 2016 and 2018, respectively. He was a recipient of the Best Paper
Award at the International Conference on Electronics, Information, and Communication (ICEIC), in 2021. He serves as a Guest Editor for Frontiers in Electronics, and as a Reviewer of IEEE TRANSACTIONS ON BIOMEDICAL
CIRCUITS AND SYSTEMS, IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS-II: EXPRESS BRIEFS, IEEE SENSORS JOURNAL, and IEEE ACCESS.

In-Chul Hwang, Department of Electrical and Electronics Engineering, Kangwon National University, Chuncheon, South Korea

In-Chul Hwang (Senior Member, IEEE) received the B.S., M.S., and Ph.D. degrees from Korea University, Seoul, South Korea, in 1993, 1995, and 2000, respectively.,He was a Postdoctoral Associate with the Coordinated Science Laboratory, University of Illinois at Urbana–Champaign, Urbana, IL, USA, from 2000 to 2001. In 2001, he joined Samsung Electronics, System LSI Division, Giheung-gu, South Korea. Since 2007, he has been with the Department of Electrical and Electronics Engineering, Kangwon National University, Chuncheon, South Korea, where he is currently a Professor. He was a Visiting Scholar with the Georgia Institute of Technology, Atlanta, GA, USA, in 2012. His current research interests include digital PLL for RFIC and digital LDO for dynamic-voltage and frequency scaling applications