Seungjun Lee
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Seungjun Lee has a total of 6 co-authors. Here are the top co-authors by number of shared publications:
- Hyungil Chae
Department of Electrical Engineering, Konkuk University, Seoul, South Korea
3 shared publications - Juyong Lee
Department of Electrical and Electronic Engineering, Konkuk University, Seoul 05029, Korea
2 shared publications - Dongsik Lee
Department of Electrical Engineering, Konkuk University, Seoul, South Korea
1 shared publication - Jihyun Baek
Department of Electrical and Electronic Engineering, Konkuk University, Seoul 05029, Korea
1 shared publication - Joohwan Jin
Department of Electrical and Electronic Engineering, Konkuk University, Seoul 05029, Korea
1 shared publication - Kihyun Kim
Korea Advanced Institute of Science and Technology (KAIST)
1 shared publication
Latest Publications
- 28 September 2023
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Circuits and Systems II: Express Briefs
- Vol. 71 (3) , 1067-1071
A 150-MS/s, 65-dB SNDR Fully Passive Bandpass Noise-Shaping SAR ADC
A fully passive bandpass (BP) noise-shaping (NS) successive approximation register (SAR) analog-to-digital converter (ADC) operating at a sampling rate of 150 MS/s is proposed. The proposed ADC structure is acquired by applying z to -z2 transformation to a fully passive lowpass (LP) NS-SAR ADC structure. Therefore, the proposed BP NS-SAR ADC inherits most of the advantages of the existing NS-SAR ADCs and achieves high energy efficiency and hardware simplicity. The prototype ADC was fabricated in a 28-nm CMOS process and achieved a signal-to-noise-distortion of 65.44 dB with a bandwidth of 18.75 MHz. The power consumption is 2.184mW and the Schreier figure-of-merit is 164.8 dB.
- 28 September 2023
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Circuits and Systems II: Express Briefs
- Vol. 71 (3) , 1067-1071
A 150-MS/s, 65-dB SNDR Fully Passive Bandpass Noise-Shaping SAR ADC
A fully passive bandpass (BP) noise-shaping (NS) successive approximation register (SAR) analog-to-digital converter (ADC) operating at a sampling rate of 150 MS/s is proposed. The proposed ADC structure is acquired by applying z to -z2 transformation to a fully passive lowpass (LP) NS-SAR ADC structure. Therefore, the proposed BP NS-SAR ADC inherits most of the advantages of the existing NS-SAR ADCs and achieves high energy efficiency and hardware simplicity. The prototype ADC was fabricated in a 28-nm CMOS process and achieved a signal-to-noise-distortion of 65.44 dB with a bandwidth of 18.75 MHz. The power consumption is 2.184mW and the Schreier figure-of-merit is 164.8 dB.
- Open Access
Readout Integrated Circuit for Small-Sized and Low-Power Gas Sensor Based on HEMT Device
This paper presents a small-sized, low-power gas sensor system combining a high-electron-mobility transistor (HEMT) device and readout integrated circuit (ROIC). Using a semiconductor-based HEMT as a gas-sensing device, it is possible to secure high sensitivity, reduced complexity, low power, and small size of the ROIC sensor system. Unlike existing gas sensors comprising only HEMT elements, the proposed sensor system has both an ROIC and a digital controller and can control sensor operation through a simple calibration process with digital signal processing while maintaining constant performance despite variations. The ROIC mainly consists of a transimpedance amplifier (TIA), a negative-voltage generator, and an analog-to-digital converter (ADC) and is designed to match a minimum target detection unit of 1 ppm for hydrogen. The prototype ROIC for the HEMT presented herein was implemented in a 0.18 µm complementary metal–oxide–semiconductor (CMOS) process. The total measured power consumption and detection unit of the proposed ROIC for hydrogen gas were 3.1 mW and 2.6 ppm, respectively.
Open AccessReadout Integrated Circuit for Small-Sized and Low-Power Gas Sensor Based on HEMT Device
This paper presents a small-sized, low-power gas sensor system combining a high-electron-mobility transistor (HEMT) device and readout integrated circuit (ROIC). Using a semiconductor-based HEMT as a gas-sensing device, it is possible to secure high sensitivity, reduced complexity, low power, and small size of the ROIC sensor system. Unlike existing gas sensors comprising only HEMT elements, the proposed sensor system has both an ROIC and a digital controller and can control sensor operation through a simple calibration process with digital signal processing while maintaining constant performance despite variations. The ROIC mainly consists of a transimpedance amplifier (TIA), a negative-voltage generator, and an analog-to-digital converter (ADC) and is designed to match a minimum target detection unit of 1 ppm for hydrogen. The prototype ROIC for the HEMT presented herein was implemented in a 0.18 µm complementary metal–oxide–semiconductor (CMOS) process. The total measured power consumption and detection unit of the proposed ROIC for hydrogen gas were 3.1 mW and 2.6 ppm, respectively.
- Open Access
- 15 August 2021
- Published by MDPI AG in Electronics
- Vol. 10 (16) , 1968
A Pipelined Noise-Shaping SAR ADC Using Ring Amplifier
In this study, a pipelined noise-shaping successive-approximation register analog-to-digital converter (PLNS-SAR ADC) structure was proposed to achieve high resolution and to be free from comparator design requirements. The inter-stage amplifier and integrator of the PLNS-SAR ADC were implemented through a ring amplifier with high gain and speed. The ring amplifier was designed to improve power efficiency and be tolerant to process–voltage–temperature (PVT) variation, and uses a single loop common-mode feedback (CMFB) circuit. By processing residual signals with a single ring amplifier, power efficiency can be maximized, and a low-power system with 30% lower power consumption than that of a conventional PLNS-SAR ADC is implemented. With a high-gain ring amplifier, noise leakage is greatly suppressed, and a structure can be implemented that is tolerant of mismatches between the analog loop and digital correction filters. The measured signal to noise distortion ratio (SNDR) is 70 dB for a 5.15 MHz bandwidth (BW) at a 72 MS/s sampling rate (Fs) with an oversampling ratio (OSR) of 7, and the power consumption is 2.4 mW. The (= SNDR + BW/Power) is 163.5 dB. The proposed structure in this study can achieve high resolution and wide BW with good power efficiency, without a filter calibration process, through the use of a ring amplifier in the PLNS-SAR ADC.- 15 August 2021
- Published by MDPI AG in Electronics
- Vol. 10 (16) , 1968
Open AccessA Pipelined Noise-Shaping SAR ADC Using Ring Amplifier
In this study, a pipelined noise-shaping successive-approximation register analog-to-digital converter (PLNS-SAR ADC) structure was proposed to achieve high resolution and to be free from comparator design requirements. The inter-stage amplifier and integrator of the PLNS-SAR ADC were implemented through a ring amplifier with high gain and speed. The ring amplifier was designed to improve power efficiency and be tolerant to process–voltage–temperature (PVT) variation, and uses a single loop common-mode feedback (CMFB) circuit. By processing residual signals with a single ring amplifier, power efficiency can be maximized, and a low-power system with 30% lower power consumption than that of a conventional PLNS-SAR ADC is implemented. With a high-gain ring amplifier, noise leakage is greatly suppressed, and a structure can be implemented that is tolerant of mismatches between the analog loop and digital correction filters. The measured signal to noise distortion ratio (SNDR) is 70 dB for a 5.15 MHz bandwidth (BW) at a 72 MS/s sampling rate (Fs) with an oversampling ratio (OSR) of 7, and the power consumption is 2.4 mW. The (= SNDR + BW/Power) is 163.5 dB. The proposed structure in this study can achieve high resolution and wide BW with good power efficiency, without a filter calibration process, through the use of a ring amplifier in the PLNS-SAR ADC.