A Transistor-Level Design and Verification of a Real-Time Inductor Health Monitoring System for Current-Mode DC-DC Converters
- 주제(키워드) PMIC , DC-DC Converter , Health monitoring , Inductor
- 발행기관 서강대학교 일반대학원
- 지도교수 Sung-Wan Hong
- 발행년도 2026
- 학위수여년월 2026. 2
- 학위명 석사
- 학과 및 전공 일반대학원 전자공학과
- 실제URI http://www.dcollection.net/handler/sogang/000000082270
- UCI I804:11029-000000082270
- 본문언어 영어
- 저작권 논문은 저작권에 의해 보호받습니다.
초록(요약문)
본 논문에서는 전류 모드 DC-DC 컨버터의 인덕터 상태를 실시간으로 모니터링하는 새로운 완전 집적형 시스템을 제안한다. 제안된 시스템은 컨버터의 동작 중단이나 외부 측정 장비 없이, 내장된 전류 센서와 전용 온칩 로직을 활용하여 인덕터의 상태를 지속적으로 추적한다. 이를 위해 부하 변동에 영향을 받지 않는 정밀한 측정을 위해 온칩 카운터 기반의 시간-디지털 변환(TDC) 기법과 전용 테스트 전류 주입 방식을 핵심으로 사용한다. 제안된 회로를 180nm CMOS 공정으로 설계하고 시뮬레이션한 결과, 인덕턴스가 0.5µH에서 1.5µH로 열화될 때 시스템의 출력 값이 5.1에서 16.0으로 선형적인 증가를 보이며 점진적인 성능 저하를 성공적으로 감지함을 확인하였다. 이러한 실시간 모니터링 기능은 데이터 센터와 같이 높은 신뢰성이 요구되는 시스템의 예측 유지보수 기술을 향상시키고, 전력 관리 집적 회로(PMIC)의 전반적인 신뢰도를 높이는 데 효과적으로 활용될 수 있음을 보여준다.
more초록(요약문)
This thesis presents a novel, fully integrated system for real-time inductor health monitoring in current-mode DC-DC converters. Without requiring converter shutdown or external measurement equipment, the proposed system continuously tracks the inductor's health by utilizing the converter's intrinsic current sensor and dedicated on-chip logic. Two key ideas form the core of this system. First, to accurately measure the switching ON-Time (dt), which varies with load and inductance in current-mode control, a Time-to- Digital Conversion (TDC) technique using an on-chip counter is introduced, replacing less reliable analog methods. Second, to ensure consistent and reliable measurements isolated from load condition effects, a dedicated test current is injected into the system during the monitoring phase. To validate the proposed system, the entire circuit was designed at the transistor level using a 180nm CMOS process and simulated in the Cadence Spectre environment. The simulation results demonstrate that as the inductance degrades from 0.5 µH to 1.5 µH, the system's output metric shows a clear, linear increase from 5.1 to 16.0. This confirms that the proposed circuit can successfully detect gradual inductor degradation. This research is expected to contribute to enhancing the reliability of power management integrated circuits (PMICs) and advancing predictive maintenance technologies for high-reliability systems such as data centers.
more목차
I. Introduction 1
1.1 Background and Motivation 1
1.2 Conventional Inductor Health-Monitoring Techniques and Their Limitations 2
1.3 Objectives and Organization of the Thesis 3
II. PROPOSED INDUCTOR HEALTH MONITORING SYSTEM 4
2.1 Fundamentals of DC-DC Buck Converters 4
2.2 Control Methods for DC-DC Converters 6
2.2.1 Voltage-Mode Control 6
2.2.2 Architecture and Operation of Current-Mode Control 8
2.3 Fundamental Principle of Inductance Measurement 10
III. THE PROPOSED INDUCTOR HEALTH MONITORING SYSTEM 11
3.1 Concept of the Proposed Monitoring System 11
3.2 Test Current Injection for Consistent Measurement 13
3.3 Time-to-Digital Conversion for Accurate Timing Measurement 13
IV. TRANSISTOR-LEVEL CIRCUIT IMPLEMENTATION 15
4.1 Overall Architecture of the Target DC-DC Converter 15
4.2 Design of the Current Sensor 16
4.3 Design of the Sample-and-Hold Circuit 17
4.3 Design of the Time-to-Digital Conversion Circuit 18
V. SIMULATION AND VERIFICATION 19
5.1 Simulation Setup 19
5.2 Simulation Results and Analysis 19
Ⅵ. CONCLUSION 21
References 22
