Charge Pump Research Articles

A reconfigurable Buck-Boost Cross-Coupled charge Pump

This paper presents a reconfigurable buck-boost Charge Pump (CP) based on the cross-coupled topology. The proposed CP is a switched capacitor (SC) converter merging different ratios and operation modes in one topology. The converter is able to step-up or step-down the input voltage at the output only by controlling the external connections of the circuit. By achieving various conversion ratios and operation modes, higher efficiency levels are performed maximizing the power that is delivered to the load. The reconfigurable buck-boost CP has been designed in 65 nm TSMC CMOS technology and covers an input voltage range from 1.6 V to 3.2 V and an output voltage range also from 1.6 V to 3.2 V in the boost mode and an input voltage range from 2.6 V to 3.6 V and an output voltage range from 1.4 to 1.8 V in the buck mode. In addition, efficiency estimation analysis is presented and proves how parasitic capacitances of flying capacitors affect the overall efficiency of a multi-ratio converter. The converter indicates peak efficiency equal to 77 % and delivers up to 4 mA load current.

Hofstadter-Toda spectral duality and quantum groups

The Hofstadter model allows to describe and understand several phenomena in condensed matter such as the quantum Hall effect, Anderson localization, charge pumping, and flat-bands in quasiperiodic structures, and is a rare example of fractality in the quantum world. An apparently unrelated system, the relativistic Toda lattice, has been extensively studied in the context of complex nonlinear dynamics, and more recently for its connection to supersymmetric Yang-Mills theories and topological string theories on Calabi-Yau manifolds in high-energy physics. Here we discuss a recently discovered spectral relationship between the Hofstadter model and the relativistic Toda lattice which has been later conjectured to be related to the Langlands duality of quantum groups. Moreover, by employing similarity transformations compatible with the quantum group structure, we establish a formula parametrizing the energy spectrum of the Hofstadter model in terms of elementary symmetric polynomials and Chebyshev polynomials. The main tools used are the spectral duality of tridiagonal matrices and the representation theory of the elementary quantum group.

A charge pump phase-locked loop with low phase noise based on ring oscillator

A charge pump phase-locked loop with low phase noise based on ring oscillator

Design of a low-power and high-efficiency charge pump

Design of a low-power and high-efficiency charge pump

Interactions Enable Thouless Pumping in a Nonsliding Lattice

A topological “Thouless” pump represents the quantized motion of particles in response to a slow, cyclic modulation of external control parameters. The Thouless pump, like the quantum Hall effect, is of fundamental interest in physics, because it links physically measurable quantities, such as particle currents, to geometric properties of the experimental system, which can be robust against perturbations and, thus, technologically useful. So far, experiments probing the interplay between topology and interparticle interactions have remained relatively scarce. Here, we observe a Thouless-type charge pump in which the particle current and its directionality inherently rely on the presence of strong interactions. Experimentally, we utilize a two-component Fermi gas in a dynamical superlattice which does not exhibit a sliding motion and remains trivial in the single-particle regime. However, when tuning interparticle interactions from zero to positive values, the system undergoes a transition from being stationary to drifting in one direction, consistent with quantized pumping in the first cycle. Remarkably, the topology of the interacting pump trajectory cannot be adiabatically connected to a noninteracting limit, highlighted by the fact that only one atom is transferred per cycle. Our experiments suggest that Thouless charge pumps are promising platforms to gain insights into interaction-driven topological transitions and topological quantum matter. Published by the American Physical Society 2024

Biorthogonal topological charge pumping in non-Hermitian systems

Biorthogonal topological charge pumping in non-Hermitian systems

High-performance coaxial reversal rotational triboelectric nanogenerator based on charge pumping strategy driving tip high voltage breakdown

Triboelectric nanogenerator (TENG) serves as an effective method for harvesting mechanical energy from the surrounding environment. Nonetheless, its practical application is hindered by issues such as inadequate charge density and wear of friction surface materials. Here, a high-performance self-supplementing coaxial inverse triboelectric nanogenerator (HSCI-TENG) based on charge pumping supplementary strategy is presented, which operates in non-contact mode and increases surface charge density with almost no friction loss. The coaxial reversal design facilitates dual-speed rotation, resulting in a significant enhancement of the output current. Furthermore, an innovative approach was employed by affixing four layers of 0.06 mm thick PET film to the storage electrode, thereby augmenting the threshold of electrode charge storage and effectively mitigating the risk of electrode breakdown. At a rotation speed of 300 rpm, the peak-to-peak voltage, peak-to-peak current, and charge transfer of HSCI-TENG are 3340 V, 360 μA and 0.97 μC, respectively. Excellent stability is demonstrated through 10000 cycle tests on the output of HSCI-TENG. In particular, the maximum output power is 770 mW at a load resistance of 8×106 Ω. The high-performance HSCI-TENG has been proven to be a stable energy source driving high voltage breakdown sensor system. The tip high voltage breakdown exhibits high frequency and continuity, with 14 breakdowns occurring within 10 seconds. Besides, HSCI-TENG has potential to serve as an energy source for high-pressure sterilization, high-pressure dust removal, and water electrolysis systems.

An NMOS output-capacitorless low-dropout regulator with dynamic-strength event-driven charge pump

In this paper, an NMOS output-capacitorless low-dropout regulator (OCL-LDO) featuring dual-loop regulation has been proposed, achieving fast transient response with low power consumption. An event-driven charge pump (CP) loop with the dynamic strength control (DSC), is proposed in this paper, which overcomes trade-offs inherent in conventional structures. The presented design addresses and resolves the large signal stability issue, which has been previously overlooked in the event-driven charge pump structure. This breakthrough allows for the full exploitation of the charge-pump structure's potential, particularly in enhancing transient recovery. Moreover, a dynamic error amplifier is utilized to attain precise regulation of the steady-state output voltage, leading to favorable static characteristics. A prototype chip has been fabricated in 65 nm CMOS technology. The measurement results show that the proposed OCL-LDO achieves a 410 nA low quiescent current (I Q) and can recover within 30 ns under 200 mA/10 ns loading change.

Topological charge pumping in tetramerized Kitaev chains with nodal loop in parameter space

We investigated the topological pumping charge of a tetramerized Kitaev chain with spatially modulated chemical potential, which hosts nodal loops in parameter space and violates particle number conservation. In the simplest case, with alternatively assigned hopping and pairing terms, we show that the model can be mapped into the Rice–Mele model by a partial particle-hole transformation and subsequently supports topological charge pumping as a demonstration of the Chern number for the ground state. Beyond this special case, analytic analysis shows that the nodal loops are conic curves. Numerical simulation of a finite-size chain indicates that the pumping charge is zero for a quasiadiabatic loop within the nodal loop and is ±1 for a quasiadiabatic passage enclosing the nodal loop. Our findings unveil the topology of Kitaev chains in parameter space.

A low voltage input boost converter with novel switch driver enhancement technology for indoor solar energy harvesting

In the indoor environment, the output voltage of a small photovoltaic cell is usually too low to charge the battery or utilize it directly. As a result, this paper proposed a low-voltage input boost converter with novel switch driver enhancement technology for indoor solar energy harvesting. The boost converter utilized switched-capacitor charge pump architecture. Compared with conventional charge pumps, the proposed boost converter uses driver enhancement technology, which improves the output current ability of the circuit and power conversion efficiency. Besides, an adaptive dead-time circuit is designed to further optimize conversion efficiency at low input voltage. The integrated circuit (IC) of the boost converter has been manufactured in a 180 nm BCD process and occupies an active chip area of 1.6mm × 0.6 mm. Experimental measurement results confirm that the voltage boost converter increased the input voltage by four times. And the lowest start-up voltage is 0.12 V. The voltage conversion efficiency is 98 % and the highest power conversion efficiency is 76.7 % at Vin of 0.5 V. The design is suitable for indoor solar energy harvesting.

Quantized Thouless charge pumping in a system with onsite quasiperiodic disorder

Quantized Thouless charge pumping in a system with onsite quasiperiodic disorder

Charge pumping with strong spin-orbit coupling: Fermi surface breathing, Berry curvature, and higher harmonic generation

Charge pumping with strong spin-orbit coupling: Fermi surface breathing, Berry curvature, and higher harmonic generation

Modelling of the refrigerant distribution in a critically charged propane heat pump cycle for performance evaluation

The investigation of heat pumps employing natural refrigerants as working fluids has gained substantial momentum, driven by increasingly stringent regulations addressing the global warming potential (GWP) and ozone depletion potential (ODP) of refrigerants. Propane (R290) stands out as an attractive option due to its low GWP and zero ODP. However, a major drawback of propane lies in its flammability. When using propane as working fluid, it will therefore be necessary to limit the total refrigerant charge within the system, without compromising on the heat pump performance. This study endeavors to address this challenge by developing a model of the refrigerant charge distribution in a critically charged heat pump system consisting of an evaporator, a compressor, a condenser, and an expansion valve. In the model, the charge distribution in the two heat exchangers is modelled in detail using a suitable void fraction correlation. For the compressor and expansion valve, a simplified model is employed, in which no refrigerant charge is calculated. Using an iterative procedure, the model can then be used to determine the coefficient of performance (COP), evaporator- and condenser pressure for a heat pump with an established total charge and heat capacity. The influence of different design and operation parameters, such as the degrees of subcooling and superheat, the volume ratio of the evaporator and the condenser, etc., can be assessed.

60Co-γ Irradiation-Induced Shift and Polarity Reversal in the Triboelectric Series of Poly(ether sulfone)s.

The sensitivity of triboelectric nanogenerators (TENGs) to the surface charge density highlights the significance of triboelectric materials and their modifications. Efforts have been directed toward developing effective strategies for increasing the surface charge density, expanding the potential applications of TENGs. This study proposes the use of irradiation technology for grafting to modify the electron-donating capability of poly(ether sulfone) (PES), thereby affording a dual benefit of enhancing the surface charge density and inducing a shift in the position of PES from negative to positive within the triboelectric series. The TENG based on grafted PES has resulted in a significant 3-fold increase in surface charge density compared to that of pristine PES, reaching 263 μC m-2. The surface charge density can be further increased to 502 μC m-2 through charge pumping. Notably, irradiation technology presents advantages over chemical grafting methods, particularly in terms of sustainability and environmental friendliness. This innovative approach shows great potential in advancing the domain of TENGs.

Self-cascode and self-biased Dickson charge pump for fast locking wide lock range PLL with reduced phase noise

The charge pump is a fundamental component in phase-locked loop (PLL) circuits, essential for generating a control voltage that adjusts the frequency and phase of the voltage-controlled oscillator (VCO) to match the input reference signal. The self-cascode and self-biased Dickson charge pump architecture presented in this work addresses several key challenges encountered in conventional PLL designs. By integrating self-cascode techniques, the charge pump exhibits enhanced charging and discharging capabilities, enabling faster locking times essential for wide lock range PLLs. This comprehensive approach offers a compact and integrated solution that simultaneously enhances locking speed, widens the lock range, reduces phase noise, and simplifies design complexity, making it highly suitable for demanding applications in communication systems, radar, and wireless technologies. The novel CP is implemented in 90-nm CMOS technology with a 1.0-V supply voltage. It is integrated with a phase-locked loop (PLL) that has a lock time of 1.0 us, a negligible reference spur, and an average power consumption of 34.7 mW. The PLL is having a wide lock range of 0.98 GHz to 2.98 GHz with a center frequency of 1.54 GHz where the phase noise is calculated to be −100.9 dBc/Hz at 1 MHz offset frequency. This makes the PLL compatible with both GSM having 1.8 GHz and Wi-Fi having 2.8 GHz frequency bands. The proposed PLL is also capable of operating at a wide range of temperatures (−27 °C, 0 °C, 27 °C, 84 °C) and at various corners (NN, FS, SF, SS, FF) making it reliable in adverse circumstances.

Liftoff of a soft-actuated micro-aerial-robot powered by triboelectric nanogenerators

Aerial insects can nimbly navigate in cluttered natural environments while they interact with delicate objects such as flowers and leaves. To achieve insect-like agility and robustness, power dense dielectric elastomer actuators (DEAs) have been developed for driving sub-gram micro-aerial-vehicles (MAVs). However, despite exhibiting muscle-like bandwidth and resilience, DEAs require a high driving voltage in the range of 1 – 2 kilovolts. This requirement poses substantial challenges for developing compact boost electronics and energy sources, which prohibit power autonomous operations of soft-actuated sub-gram MAVs. Here, we develop a compact and high power triboelectric nanogenerator (TENG) that can effectively charge a high-voltage DEA and enable the liftoff of a soft-actuated MAV. We propose an In-plane Charge Pump (ICP) design that can deliver over 1500 V and 110 mW without requiring a secondary charge pump or magnetic circuit components such as inductors or transformers. Compared to conventional free-standing mode TENGs, our ICP design shows a 280 % and 920 % increase in voltage and energy generation, respectively. When this TENG powers a DEA-driven MAV, the 160 mg robot achieves liftoff with a lift-to-weight ratio of 1.75. This result highlights the potential of powering high-voltage microrobots with energy-harvesting devices.

Design and simulation optimization of phase-locked loop structure for phase-shifting power supply

A phase-locked loop (PLL) of a phase-shifting power supply for the power system is designed in this paper. Taking the industrial frequency current as the reference signal, the input and output characteristics of the phase-frequency detector with charge pump are analyzed. In addition, the transfer function of the PLL system is analyzed by combining the passive second-order low-pass filter and the voltage-controlled oscillator. As a result, the influence of parameters such as charge pump current, phase margin, and loop bandwidth on the performance of the PLL is investigated, and the optimal parameters of each section are obtained. The results show that the optimized PLL has a locking time of 0.75 s, a pull-out range of 63.16 Hz, and a locking range of 43.82 Hz, with high stability and noise immunity.

A 3.96-4.84-GHz Dual-Path Charge Pump PLL Achieving 89.7-fsrms Integrated Jitter and −250.8-dB FOMPLL

A 3.96-4.84-GHz Dual-Path Charge Pump PLL Achieving 89.7-fs_rms Integrated Jitter and −250.8-dB FOM_PLL

How demand-side management can shape electricity generation capacity planning

Forward-looking strategies for Demand Side Management (DSM) can accelerate the clean energy transition and reduce carbon emissions if electricity load can be shaped to be better matched to the hourly availability of renewable resources. Time-varying rates are increasingly used to motivate load shifting, capitalizing on the increasing size of loads that can be easily shifted, such as electric vehicle charging and electric heat pumps. This study analyzes the hourly availability of current and renewable resources for two representative electricity grids in the USA. While many demand-management programs are currently designed to shift load to nighttime when demand is low, to use low-cost PV the opposite shift into daytime will be preferred. Given that investments in electricity generation capacity shape the grid for decades, generation capacity planning should proactively anticipate how DSM programs (and associated load shapes) will change as the generation mix changes. These future load shapes determine the optimal resources to be acquired and can be modified by DSM to facilitate variable renewable integration. Ongoing regulatory proceedings in Colorado are described as a case study for an existing decision-making process.

2D BDiode – A switchable bidirectional diode for analog electronic circuits fabricated entirely from 2D materials

The advent of two-dimensional (2D) materials has led to innovative and compact electronic devices with remarkable properties. In this work, we introduce a switchable bidirectional diode (2D BDiode), fabricated entirely using different 2D materials, that serves as a fundamental building block for various analog circuit applications. This proof-of-concept diode exhibits the ability to control the flow of current in both forward and reverse bias configurations, enabling advanced functionality in the realm of analog circuit design. We provide a SPICE-based model for the diode based on current-voltage device characterization, capturing its behavior under different biasing conditions, and finally demonstrate a few potential use cases of the 2D BDiode including AC/DC conversion, DC/AC conversion and charge pump circuits.