Min-Sun Keel | University of Illinois at Urbana-Champaign (original) (raw)

Papers by Min-Sun Keel

Research paper thumbnail of CDM-reliable T-coil techniques for high-speed wireline receivers

An inherent CDM hazard exists in T-coil circuits due to magnetic coupling. An “inductance halving... more An inherent CDM hazard exists in T-coil circuits due to magnetic coupling. An “inductance halving” technique is proposed to reduce magnetic coupling during ESD. From simulation, the proposed solution can effectively suppress voltage overshoot and minimize bandwidth degradation, compared to the conventional secondary ESD protection.

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Research paper thumbnail of An energy-efficient memory-based high-throughput VLSI architecture for convolutional networks

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Research paper thumbnail of A 140 dB Single-Exposure Dynamic-Range CMOS Image Sensor with In-Pixel DRAM Capacitor

2022 International Electron Devices Meeting (IEDM), Dec 3, 2022

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Research paper thumbnail of Design of reliable and energy-efficient high-speed interface circuits

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Research paper thumbnail of Custom test chip for system-level ESD investigations

Electrical Overstress/Electrostatic Discharge Symposium, Dec 4, 2014

A test-chip for monitoring soft failures is presented. Diagnostics include logic circuit upset de... more A test-chip for monitoring soft failures is presented. Diagnostics include logic circuit upset detection, substrate potential latchup monitors, input glitch detectors, system IDDQ monitors, and USB transmitters. Powered TLP testing and IEC61000-4-2 ESD produce different failures. Also, different failures are reported for mobile systems and those powered through grounded supplies.

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Research paper thumbnail of Energy-efficient and high throughput sparse distributed memory architecture

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Research paper thumbnail of ESD Self-Protection of High-Speed Transceivers Using Adaptive Active Bias Conditioning

IEEE Transactions on Device and Materials Reliability, Mar 1, 2017

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Research paper thumbnail of ESD protection networks for 3D integrated circuits

The inter-die signal interfaces in a 3D-IC are vulnerable to over-voltage stress induced by Charg... more The inter-die signal interfaces in a 3D-IC are vulnerable to over-voltage stress induced by Charged Device Model ESD. The magnitude of the stress is highly sensitive to the design of the ground distribution network on both the die and package level. It is also affected by the type of package being used. Small voltage clamping devices may be placed at inter-die receivers to mitigate the risk of gate dielectric breakdown. New ESD rule checking tools are needed for 3D-IC design automation.

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Research paper thumbnail of An energy-efficient VLSI architecture for pattern recognition via deep embedding of computation in SRAM

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Research paper thumbnail of 25Gb/s有線受信機フロントエンドのCDM信頼性T-コイル技術

IEEE Transactions on Device and Materials Reliability, 2016

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Research paper thumbnail of Charge pump with perfect current matching characteristics in phase-locked loops

Electronics Letters, 2000

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Research paper thumbnail of 適応アクティブバイアス調整を用いた高速トランシーバのESD自己保護【Powered by NICT】

IEEE Transactions on Device and Materials Reliability, 2017

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Research paper thumbnail of A 3D Touchless Hand Navigation Sensor for Small-Size and Low-Power Applications

IEEE Sensors Journal, Jul 1, 2019

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Research paper thumbnail of CDM-Reliable T-Coil Techniques for a 25-Gb/s Wireline Receiver Front-End

IEEE Transactions on Device and Materials Reliability, Dec 1, 2016

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Research paper thumbnail of A 140 dB Single-Exposure Dynamic-Range CMOS Image Sensor with In-Pixel DRAM Capacitor

2022 International Electron Devices Meeting (IEDM)

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Research paper thumbnail of Energy-efficient and high throughput sparse distributed memory architecture

2015 IEEE International Symposium on Circuits and Systems (ISCAS), 2015

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Research paper thumbnail of Indirect-ToF system optimization for sensing range enhancement with patterned light source and adaptive binning

An indirect time-of-flight (ToF) system is presented to extend the depth-sensing range. The propo... more An indirect time-of-flight (ToF) system is presented to extend the depth-sensing range. The proposed 4-tap ToF sensor system is equipped with a patterned light source in the transmitter side, focusing the optical power on the selected spot points, maintaining the average optical power compared with the conventional flood-type light source. By focusing the optical power on the spots, the signal-to-noise ratio and demodulation contrast (DC) are enhanced, and the depth noise (precision) performance is improved. The adaptive binning scheme is implemented on the receiver side to decide the optimal binning method according to the amount of ambient light; the DC is used as a metric for this decision. With a proper binning mode selection, the depth performance can be optimized by smaller read noise at the indoor condition, and a larger full well capacity at the outdoor condition. Finally, we achieved a 3.4× working distance increase even under the strong external light conditions.

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Research paper thumbnail of Wiggling Error Self-Calibration for Indirect ToF Image Sensors

We propose a method to self-calibrate wiggling distance error in the indirect time-of-flight (ToF... more We propose a method to self-calibrate wiggling distance error in the indirect time-of-flight (ToF) image sensor system. The basic idea is to minimize harmonic components in the demodulation signals by equivalent waveform shaping. During the exposure time, demodulation signals are phase-shifted gradually at every demodulation pulse cycle up to a specific phase delay, to emulate sinusoid signals with the smallest harmonics. The proposed phase delay control circuit was implemented in the 1.2-Mpixel indirect ToF sensor. The optimal phase delay is found by the simulation and verified by the measurement results. The proposed wiggling self-calibration achieved a distance error of less than 4 mm with an optimal phase delay of 123°, which is about 12 times smaller than that of the uncalibrated case.

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Research paper thumbnail of A VGA Indirect Time-of-Flight CMOS Image Sensor With 4-Tap 7-μm Global-Shutter Pixel and Fixed-Pattern Phase Noise Self-Compensation

IEEE Journal of Solid-State Circuits, 2019

A video graphics array (VGA) (640 <inline-formula> <tex-math notation="LaTeX"&... more A video graphics array (VGA) (640 <inline-formula> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 480) indirect time-of-flight (ToF) CMOS image sensor has been designed with 4-tap 7-<inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> global-shutter pixel in 65-nm back-side illumination (BSI) process. With a 4-tap pixel structure, we achieved motion artifact-free depth map. Peak current during exposure time has been reduced by current spreading with constant delay chain in the photo-gate driver. Column fixed-pattern phase noise (FPPN) from the constant delay chain is self-compensated by the proposed time-interleaving technique with the two inversely directional clock chains in the photo-gate driver. Quantum efficiency (QE) and demodulation contrast (DC) have been optimized by using appropriate optical engineering techniques with an optimal silicon thickness. As a result, QE of 34% at 940-nm near-infrared and high DC of 86% at 100-MHz modulation frequency have been achieved. In addition, motion artifact and column FPPN are successfully removed in the depth map. The proposed ToF sensor shows depth noise less than 0.57% with 940-nm illuminator over the working distance up to 4 m, and consumes only 160 mW for VGA output at 60 frames/s.

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Research paper thumbnail of A 3D Touchless Hand Navigation Sensor for Small-size and Low-power Applications

IEEE Sensors Journal, 2019

Modern electronic devices have been designed to allow many types of human–machine interfaces with... more Modern electronic devices have been designed to allow many types of human–machine interfaces with flexibility. One of the user-friendly navigations is interfacing a human hand, but the implementation using conventional devices, such as additional controllers or image sensors, requires a larger size or a higher power. In this paper, a small-size and low-power 3D touchless hand navigation sensor (HNS) is presented. The proposed HNS based on a proximity sensor consists of an LED and integrated photosensors. The <inline-formula> <tex-math notation="LaTeX">$x$ </tex-math></inline-formula>- and <inline-formula> <tex-math notation="LaTeX">$y$ </tex-math></inline-formula>-directions can be controlled by tilting a hand in the x-axis and the y-axis without the need of swiping. The distance between the hand and HNS in the z-axis is calculated by the photosensor dedicated to the z-axis. The experimental results show that the proposed HNS is superior to other types of navigation sensors in terms of size and power.

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Research paper thumbnail of CDM-reliable T-coil techniques for high-speed wireline receivers

An inherent CDM hazard exists in T-coil circuits due to magnetic coupling. An “inductance halving... more An inherent CDM hazard exists in T-coil circuits due to magnetic coupling. An “inductance halving” technique is proposed to reduce magnetic coupling during ESD. From simulation, the proposed solution can effectively suppress voltage overshoot and minimize bandwidth degradation, compared to the conventional secondary ESD protection.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of An energy-efficient memory-based high-throughput VLSI architecture for convolutional networks

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Research paper thumbnail of A 140 dB Single-Exposure Dynamic-Range CMOS Image Sensor with In-Pixel DRAM Capacitor

2022 International Electron Devices Meeting (IEDM), Dec 3, 2022

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Research paper thumbnail of Design of reliable and energy-efficient high-speed interface circuits

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Research paper thumbnail of Custom test chip for system-level ESD investigations

Electrical Overstress/Electrostatic Discharge Symposium, Dec 4, 2014

A test-chip for monitoring soft failures is presented. Diagnostics include logic circuit upset de... more A test-chip for monitoring soft failures is presented. Diagnostics include logic circuit upset detection, substrate potential latchup monitors, input glitch detectors, system IDDQ monitors, and USB transmitters. Powered TLP testing and IEC61000-4-2 ESD produce different failures. Also, different failures are reported for mobile systems and those powered through grounded supplies.

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Research paper thumbnail of Energy-efficient and high throughput sparse distributed memory architecture

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Research paper thumbnail of ESD Self-Protection of High-Speed Transceivers Using Adaptive Active Bias Conditioning

IEEE Transactions on Device and Materials Reliability, Mar 1, 2017

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Research paper thumbnail of ESD protection networks for 3D integrated circuits

The inter-die signal interfaces in a 3D-IC are vulnerable to over-voltage stress induced by Charg... more The inter-die signal interfaces in a 3D-IC are vulnerable to over-voltage stress induced by Charged Device Model ESD. The magnitude of the stress is highly sensitive to the design of the ground distribution network on both the die and package level. It is also affected by the type of package being used. Small voltage clamping devices may be placed at inter-die receivers to mitigate the risk of gate dielectric breakdown. New ESD rule checking tools are needed for 3D-IC design automation.

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Research paper thumbnail of An energy-efficient VLSI architecture for pattern recognition via deep embedding of computation in SRAM

Bookmarks Related papers MentionsView impact

Research paper thumbnail of 25Gb/s有線受信機フロントエンドのCDM信頼性T-コイル技術

IEEE Transactions on Device and Materials Reliability, 2016

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Research paper thumbnail of Charge pump with perfect current matching characteristics in phase-locked loops

Electronics Letters, 2000

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Research paper thumbnail of 適応アクティブバイアス調整を用いた高速トランシーバのESD自己保護【Powered by NICT】

IEEE Transactions on Device and Materials Reliability, 2017

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Research paper thumbnail of A 3D Touchless Hand Navigation Sensor for Small-Size and Low-Power Applications

IEEE Sensors Journal, Jul 1, 2019

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Research paper thumbnail of CDM-Reliable T-Coil Techniques for a 25-Gb/s Wireline Receiver Front-End

IEEE Transactions on Device and Materials Reliability, Dec 1, 2016

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Research paper thumbnail of A 140 dB Single-Exposure Dynamic-Range CMOS Image Sensor with In-Pixel DRAM Capacitor

2022 International Electron Devices Meeting (IEDM)

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Energy-efficient and high throughput sparse distributed memory architecture

2015 IEEE International Symposium on Circuits and Systems (ISCAS), 2015

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Indirect-ToF system optimization for sensing range enhancement with patterned light source and adaptive binning

An indirect time-of-flight (ToF) system is presented to extend the depth-sensing range. The propo... more An indirect time-of-flight (ToF) system is presented to extend the depth-sensing range. The proposed 4-tap ToF sensor system is equipped with a patterned light source in the transmitter side, focusing the optical power on the selected spot points, maintaining the average optical power compared with the conventional flood-type light source. By focusing the optical power on the spots, the signal-to-noise ratio and demodulation contrast (DC) are enhanced, and the depth noise (precision) performance is improved. The adaptive binning scheme is implemented on the receiver side to decide the optimal binning method according to the amount of ambient light; the DC is used as a metric for this decision. With a proper binning mode selection, the depth performance can be optimized by smaller read noise at the indoor condition, and a larger full well capacity at the outdoor condition. Finally, we achieved a 3.4× working distance increase even under the strong external light conditions.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Wiggling Error Self-Calibration for Indirect ToF Image Sensors

We propose a method to self-calibrate wiggling distance error in the indirect time-of-flight (ToF... more We propose a method to self-calibrate wiggling distance error in the indirect time-of-flight (ToF) image sensor system. The basic idea is to minimize harmonic components in the demodulation signals by equivalent waveform shaping. During the exposure time, demodulation signals are phase-shifted gradually at every demodulation pulse cycle up to a specific phase delay, to emulate sinusoid signals with the smallest harmonics. The proposed phase delay control circuit was implemented in the 1.2-Mpixel indirect ToF sensor. The optimal phase delay is found by the simulation and verified by the measurement results. The proposed wiggling self-calibration achieved a distance error of less than 4 mm with an optimal phase delay of 123°, which is about 12 times smaller than that of the uncalibrated case.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of A VGA Indirect Time-of-Flight CMOS Image Sensor With 4-Tap 7-μm Global-Shutter Pixel and Fixed-Pattern Phase Noise Self-Compensation

IEEE Journal of Solid-State Circuits, 2019

A video graphics array (VGA) (640 <inline-formula> <tex-math notation="LaTeX"&... more A video graphics array (VGA) (640 <inline-formula> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 480) indirect time-of-flight (ToF) CMOS image sensor has been designed with 4-tap 7-<inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> global-shutter pixel in 65-nm back-side illumination (BSI) process. With a 4-tap pixel structure, we achieved motion artifact-free depth map. Peak current during exposure time has been reduced by current spreading with constant delay chain in the photo-gate driver. Column fixed-pattern phase noise (FPPN) from the constant delay chain is self-compensated by the proposed time-interleaving technique with the two inversely directional clock chains in the photo-gate driver. Quantum efficiency (QE) and demodulation contrast (DC) have been optimized by using appropriate optical engineering techniques with an optimal silicon thickness. As a result, QE of 34% at 940-nm near-infrared and high DC of 86% at 100-MHz modulation frequency have been achieved. In addition, motion artifact and column FPPN are successfully removed in the depth map. The proposed ToF sensor shows depth noise less than 0.57% with 940-nm illuminator over the working distance up to 4 m, and consumes only 160 mW for VGA output at 60 frames/s.

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Research paper thumbnail of A 3D Touchless Hand Navigation Sensor for Small-size and Low-power Applications

IEEE Sensors Journal, 2019

Modern electronic devices have been designed to allow many types of human–machine interfaces with... more Modern electronic devices have been designed to allow many types of human–machine interfaces with flexibility. One of the user-friendly navigations is interfacing a human hand, but the implementation using conventional devices, such as additional controllers or image sensors, requires a larger size or a higher power. In this paper, a small-size and low-power 3D touchless hand navigation sensor (HNS) is presented. The proposed HNS based on a proximity sensor consists of an LED and integrated photosensors. The <inline-formula> <tex-math notation="LaTeX">$x$ </tex-math></inline-formula>- and <inline-formula> <tex-math notation="LaTeX">$y$ </tex-math></inline-formula>-directions can be controlled by tilting a hand in the x-axis and the y-axis without the need of swiping. The distance between the hand and HNS in the z-axis is calculated by the photosensor dedicated to the z-axis. The experimental results show that the proposed HNS is superior to other types of navigation sensors in terms of size and power.

Bookmarks Related papers MentionsView impact