This article presents a step-up switched-capacitor (SC) sigma converter with fast transient, high efficiency, and high accuracy for light detection and ranging (LiDAR) receiver applications. The proposed sigma converter combines an unregulated SC converter in the high-voltage (HV) domain and a low-dropout (LDO) regulator in the low-voltage (LV) domain, achieving step-up voltage conversion through a series output connection. The unregulated SC converter operates in the HV domain, achieves high-efficiency power delivery, and boosts voltage in a very high density. At the same time, the LDO ensures fast transient response and accurate load regulation in the LV domain. The prototype achieves 5–16 V voltage boosting with a peak conversion efficiency of 94% at a maximum output power of 3.6 W and up to 152 mW/mm³ power density. The LDO regulator ensures accurate load regulation of 44 μV/mA (0.063% error with full load range) and fast load transient response of 180 ns during 0–200 mA load current transition.

This article analyzes the recently emerged resonant current-mode (RCM) topology and compares it with conventional voltage-mode (VM) rectifiers. Building upon prior RCM designs, a three-phase RCM rectifier is proposed to achieve a wider output power range and higher power efficiency, enabled by residual-free charge delivery through a bypass-capacitor-based mechanism. By incorporating a low-power freewheeling phase, the rectifier supports in situ output voltage regulation and inherently enables load-shift-keying (LSK)-based uplink data transfer, eliminating the need for additional voltage regulators or data links. A digitally assisted adaptive zero-voltage switching (ZVS) technique with fast delay compensation is implemented to minimize conduction losses in the power stage. Fabricated in a 180-nm CMOS process, the prototype occupies a silicon area of 0.4 mm². Measurement results demonstrate reliable hysteresis output regulation at 3.3V, while the output voltage can span a wide range from 2.2 to 4.4 V. The output power ranges from 0.4 to 209.4 mW. A peak power conversion efficiency (PCE) of 94.5% is achieved at 90.8-mW output power. The PCE remains above 80% for all tested output voltages (2.2, 3.3, 4.4 V) when the load current exceeds 1mA.

Triboelectric nanogenerators (TENGs) have emerged as a promising solution for powering Internet of Things (IoT) sensor nodes and wearable electronics, owing to their use of low-cost, lightweight, and environmentally friendly materials. However, the distinctive characteristics of their electrical output, such as high voltage and time-varying internal capacitance, pose significant challenges for the design of efficient power management circuits (PMCs). The high output voltage of TENGs, which often exceeds the safe operating limits of integrated-circuit (IC) technologies, renders conventional IC-based PMCs unsuitable for optimal energy extraction. As a result, board-level PMCs, free from these voltage constraints, are essential for effectively managing the output power of TENGs. This article presents a comprehensive classification and critical review of recent board-level PMC designs tailored for TENG applications. Using a generic block diagram as a framework, various implementation strategies for each functional block are analyzed, highlighting their respective benefits and limitations. Particular focus is given to switching-stage configurations around the rectifier, which enable advanced techniques, such as synchronous electric charge extraction and synchronous switched harvesting on inductor. A comparative analysis of representative PMCs is conducted based on key mechanical and electrical performance metrics. Finally, unresolved challenges and promising research directions are discussed, providing insights into future development of high-efficiency TENG-based energy harvesting systems.

Triboelectric nanogenerators (TENGs) have emerged as a promising power solution for autonomous sensors, as they can be constructed using low-cost, lightweight, and environmentally friendly materials. However, the design of the ensuing power management circuit, intended to maximize energy extraction from the TENG, remains a challenge for circuit designers at both board and integrated circuit levels, especially due to the unique properties of the TENG output signal. Among the different circuit topologies proposed in the literature, this article focuses on the full-wave rectifier (FWR) with a dual output (DO). It is proposed to incorporate a switch at the input of the FWR-DO to increase the energy extracted from the TENG. The switch is instantaneously closed in synchronization with the maximum and minimum separation between electrodes, thereby generating a short circuit across the TENG. As a result of this short-circuit, the voltage at the two outputs of the FWR-DO can be adjusted independently to optimize energy extraction in both half cycles, which is not possible in conventional FWR-DOs. The proposed circuit, including the synchronized input switch, is evaluated theoretically, by simulations, and experimentally using an in-house fabricated TENG with a contact-separation topology. In addition, its performance is compared with that obtained using conventional FWR and FWR-DO topologies. According to the results reported herein, the incorporation of the synchronized input switch generates an improvement in the energy extraction that depends on the symmetry of the voltage–charge plot related to the TENG. For the TENG under test, the energy improvement factor (with respect to FWR-DO) is 18% when the switch is incorporated.

This paper proposes an on-chip sigma regulation system for the accurate and power-efficient control of piezoelectric resonator (PR)-based DC-DC converters to address the challenges of conventional off-chip controllers. A zero-standby sigma-mode is implemented for transient response/output power improvement. Peak efficiencies of 91.2% and 90.7% are achieved for the PR converter and the PR-sigma converter respectively.

Due to the better performance of the Wide Band Gap (WBG) devices, there has been a paradigm shift toward WBG-based power modules for diverse applications like Electric Vehicles (EVs). However, the high parasitic inductance value of power modules hinders these devices from unlocking their full potential. Therefore, this paper comprehensively reviews SiC-based Single Side Cooling (SSC) power modules that benefit from low parasitic inductance. The paper also discusses the need to develop newer power modules using modern packaging methods. The surveyed power modules are categorized into three main groups, namely wire bonding, hybrid, and 3D packaging methods. This classification contains several vital parameters of the studied power modules, such as nominal and Double Pulse Tests (DPT) power ratings, parasitic inductance, size, etc. The main features and characteristics corresponding to the reviewed power modules' packaging methods and techniques are also briefly described. Finally, a thorough discussion about challenges and future trends is highlighted before concluding the paper.

This article presents a self-powered adaptive piling-up rectifier-less synchronized-switch-harvesting-on-inductor (APReL-SSHI) interface for piezoelectric energy harvesting. The proposed interface introduces two distinct operational modes, energy transfer mode and voltage piling-up mode, that adaptively select the optimal mode based on varying vibration excitation levels to maximize energy extraction. This adaptive mechanism addresses the narrow optimal rectified voltage range (ORVR) limitation inherent in conventional S-SSHI rectifiers by enabling capacitor charging beyond standard thresholds. Experimental results demonstrate that the proposed APReL-SSHI circuit achieves up to 5.27 times the maximum output power compared to a full-bridge rectifier and expands the ORVR by 4.16 times compared to a conventional S-SSHI circuit. Consequently, the APReL-SSHI delivers superior balance between these two key performance metrics compared to existing state-of-The-Art rectifiers. Moreover, the circuit uniquely exhibits a secondary output power peak, reaching approximately 94% of maximum power when operated above the standard maximum power point (MPP) voltage. Under constant input conditions, the voltage associated with this secondary power peak is easily adjustable, thereby facilitating direct voltage matching for diverse load requirements and achieving near-MPP tracking efficiency of 94% without the need for an additional MPPT controller.

A triboelectric nanogenerator (TENG) is a novel device that utilizes contact electrification and electrostatic induction to convert mechanical energy into electrical energy. Its characteristics include high energy density and flexibility, enabling self-powering of electronic devices by harvesting mechanical energy from the environment. Its applications include biomedical devices, wearable electronics, and Internet-of-Things (IoT) sensors. Despite these advantages, extracting electrical energy from TENG remains challenging due to its time-varying nature and low internal capacitance. Effective power-management techniques are essential for TENG energy-harvesting systems, yet research on dedicated integrated power-conversion methods is currently limited. Given the growing interest in TENG, a comprehensive exploration of energy-harvesting systems is critically necessary. This article synthesizes and compares current advancements in triboelectric energy-harvesting systems, emphasizing strategies to enhance output power through various power-conversion techniques. Additionally, it explores techniques employed in other energy-harvesting systems to inspire innovative approaches in TENG system design.

This article presents a reconfigurable piezoelectric harvester array (RPA) designed for multi-input systems, which dynamically configures its structure based on the intensity of ambient vibrations. The proposed architecture enhances system efficiency by eliminating dc–dc converters and achieving maximum power point tracking through a single power stage. It also widens the input range by serially connecting PEH units, enabling operation at lower excitation levels. Additionally, this series connection reduces equivalent parasitic capacitance, improving flip efficiency and maximum output power improving rate (MOPIR).The proposed RPA is employed with classical parallel-synchronous switch harvesting on inductor technology and implemented using a 180 nm CMOS process. Experimental results demonstrate a conversion efficiency of up to 78%, an MOPIR of 5.93, and a minimum input voltage of 0.36 V. This highly integrated, wide-input-range, and energy-efficient scheme offers a novel approach to miniaturizing PEH systems. We present detailed design principles, operational mechanisms, and performance metrics, highlighting the RPA’s potential as a scalable and environmentally friendly solution for powering next-generation Internet of Thing devices.