Vision

The rapid advancement of Internet-of-Things (IoT) sensor platform has been penetrating all corners of our lives, presenting unprecedented levels of demands for power efficiency, computation latency, task complexity, and form factors. The next evolutionary phase of IoT platform will be realized with the following four key features toward further enriching our daily lives: Tiny, Sensory, Intelligent, and Wireless.


My ultimate research goal is to Democratize these features of IoT platform, envisioning a future where everyone can enjoy the benefits. To arrive at this goal, the Integrated Circuit (IC) designers will need to develop highly integrated System-on-Chips (SoCs) that operate efficiently within constrained energy sources and silicon area.

My research focuses on power-efficient analog/mixed-signal ICs for Biomedical and Neuromorphic sensor systems. I am passionate about realizing ultra-low-power, digital-friendly analog circuit architectures suitable for tiny Artificial Intelligence (AI) embedded IoT platforms.






Biomedical Sensor IC



GLY

ISSCC 2019 JSSC 2020 ISCAS 2023

  • Lead-Compensated flipped voltage follower (FVF)
    • 11.65x higher bandwidth, 3.19x less power, without noise increase
  • Widely adopted by multiple research groups
    • ISSCC 2021 (A*STAR, Singapore ๐Ÿ‡ธ๐Ÿ‡ฌ)
    • ISSCC 2022 (Fudan University, China ๐Ÿ‡จ๐Ÿ‡ณ)
    • ISSCC 2024 (KAIST, South Korea ๐Ÿ‡ฐ๐Ÿ‡ท)
  • Silver Award in 2019 Samsung HumanTech paper competition
  • ๐Ÿ“š Open-Sourced schematic parameters in ISCAS 2023
    • You are more than welcomed to copy๏ผ†paste this biomedical amplifier design ๐Ÿ˜€

BioZ2

VLSI 2020 JSSC 2022 Open Source Code

  • All-Digital ฮ”ฮฃ modulated sinewave generator
  • A sinusoidal current generator with performance improvements in:
    • 1.9~7.5x more linear, 8.9x less power, 33x less area
  • ๐Ÿ“š Open-Sourced MATLAB/Verilog Code in PhD dissertation
    • TCAS-II 2023, TCAS-II 2024 (Oregon State University, USA ๐Ÿ‡บ๐Ÿ‡ธ)
      โ†’ An improved design based on the open-source code






Neuromorphic Sensor IC



CochClass

ISSCC 2022 JSSC 2022 CAS Magazine 2023

  • The first Fully-Integrated keyword spotting chip that includes:
    • Time Domain analog feature extractor
    • Digital neural network classifier
  • Spike-friendly Neuromorphic signal processing inspired by biological cochlea
  • Technology-Scalable time domain circuits in advanced CMOS process nodes
  • IEEE Highlights (Sep. ~ Oct. 2023)
    • ๐ŸŽ‰ Highlighted in the IEEExplore Main Page
    • ๐ŸŽ‰ Top-2 in the Most Popular Articles in JSSC
    • ๐ŸŽ‰ Top-1 in the Most Popular Articles in CAS Magazine

C2-FWR

AICAS 2023

  • Low power analog signal processing circuits for intelligent audio sensors
  • Python-modeled full-wave rectifier (FWR) and Hardware-Aware Training in RNN classifier
    • Dynamic comparator and chopper
    • 31.2x less power but negligible classification accuracy drop
    • Without increase of network size
  • Best Poster Award in AICAS 2023






Research Partners

Europe ย  ย  ย  ย  ย 
Marko Kosunen Associate Professor IEEE Senior Member Aalto University Finland ๐Ÿ‡ซ๐Ÿ‡ฎ
Tobi Delbruck Professor IEEE Fellow UZH/ETH Zurich Switzerland ๐Ÿ‡จ๐Ÿ‡ญ
Shih-Chii Liu Professor IEEE Fellow UZH Switzerland ๐Ÿ‡จ๐Ÿ‡ญ
Taekwang Jang Assistant Professor IEEE Senior Member ETH Zurich Switzerland ๐Ÿ‡จ๐Ÿ‡ญ
Chang Gao Assistant Professor IEEE Member TU Delft Netherlands ๐Ÿ‡ณ๐Ÿ‡ฑ
Qinyu Chen Assistant Professor IEEE Member Leiden University Netherlands ๐Ÿ‡ณ๐Ÿ‡ฑ
Martin Andraud Assistant Professor IEEE Member UCLouvain Belgium ๐Ÿ‡ง๐Ÿ‡ช
Asia ย  ย  ย  ย  ย 
Hoi-Jun Yoo Professor IEEE Fellow KAIST South Korea ๐Ÿ‡ฐ๐Ÿ‡ท
Kyungsik Choi Assistant Professor IEEE Member SeoulTech South Korea ๐Ÿ‡ฐ๐Ÿ‡ท
Woojun Choi Assistant Professor IEEE Member Kyung Hee University South Korea ๐Ÿ‡ฐ๐Ÿ‡ท
Youngwoo Ji Assistant Professor IEEE Member Hanbat
National University
South Korea ๐Ÿ‡ฐ๐Ÿ‡ท
Sohmyung Ha Assistant Professor IEEE Senior Member NYU Abu Dhabi UAE ๐Ÿ‡ฆ๐Ÿ‡ช
America ย  ย  ย  ย  ย 
Jason Eshraghian Assistant Professor IEEE Member UC Santa Cruz United States ๐Ÿ‡บ๐Ÿ‡ธ