Charge Pump Circuit Research Articles

A Low Mismatch Current Charge Pump Applied to Phase-Locked Loops.

This paper presents a charge pump circuit with a wide output range and low current mismatch applied to phase-locked loops. In this designed structure, T-shaped analog switches are adopted to suppress the non-ideal effects of clock feedthrough, switching time mismatch, and charge injection. A source follower and current splitting circuits are proposed to improve the matching accuracy of the charging and discharging currents and reduce the current mismatch rate. A rail-to-rail high-gain amplifier with a negative feedback connection is introduced to suppress the charge-sharing effect of the charge pump. A cascode current mirror with a high output impedance is used to provide the charge and discharge currents for the charge pump, which not only improves the current accuracy of the charge pump but also increases the output voltage range. The proposed charge pump is designed and simulated based on a 65 nm CMOS process. The results show that when the power supply voltage is 1.2 V, the output current of the charge pump is 100 μA, the output voltage is in the range of 0.2~1 V, and the maximum current mismatch rate and current variation rate are only 0.21% and 1.4%, respectively.

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.

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.

Transformerless Inverter with Charge Pump Circuit Concept for PV Application

This paper introduces a new single phase transformerless photovoltaic (PV) inverter for grid connected PV systems using the concept of a charge pump. It consists of four power switches, two diodes, two capacitors and an LC filter at the output stage. The neutral of the grid is directly connected to the negative terminal of PV panel. This common ground creates a constant Common Mode (CM) voltage and zero leakage current. Meanwhile, the charge pump circuit generates the negative bus voltage for the inverter during the negative power cycle. A unipolar Sinusoidal Pulse Width Modulation (SPWM) technique is applied to the proposed inverter with three level output voltage to reduce the output current ripple and the filter requirements. The main advantages of the proposed inverter are (1) the negative polarity of the PV is directly connected to the grid, so the leakage current eliminated, (2) it has a compact size, (3) peak of output voltage is equal to input dc voltage (unlike Neutral Point Clamped (NPC) inverter, Active NPC (ANPC) and some topologies, which requires two times of the peak ac-voltage magnitude), flexible grounding configuration and high efficiency. The operating principle and analysis of the proposed topology are presented in details. Experimental results of a 500 W prototype are demonstrated to validate the proposed topology and the overall concept. The obtained results clearly verify the performance of the proposed inverter and its practical application for grid connected PV systems.

A HCI-hardened self-healing operational amplifier circuit

In this paper, a self-healing operational amplifier circuit to deal with hot carrier injection (HCI) effect is proposed. An inverter-based operational amplifier is implemented. The influence degree of HCI effect to performance of the operational amplifier is studied which utilizes an equivalent circuit model of HCI effect. A monitoring circuit is proposed to monitor the degree of HCI degradation. A charge pump circuit is utilized to generate a corresponding voltage according to the result of monitoring circuit. The output voltage of the charge pump circuit is feedback to tune the substrate voltage of the operational amplifier (and the monitoring circuit) to mitigate degradation. The simulation results show that the self-healing operational amplifier can maintain the performance at low temperature and room temperature for 50 years (and high temperature for 30 year) under HCI effect. The gain of the inverter-based operational amplifier without self-healing is reduced from 45 dB to 9.6 dB after 50 years, and the gain of the self-healing operational amplifier will maintain at about 46 dB among 50 years. The influence of HCI effect on bandwidth and phase margin is less than that of temperature and process corner. The lifetime of self-healing operational amplifier circuit is >5 times longer than lifetime of based on inverter operational amplifier circuit without self-healing. In addition, the self-healing operational amplifier is robust to process corner.

Design of Charge Pump Circuit for Stepper Motor Drive Chip

A charge pump circuit structure that can be applied to high-voltage drive circuits such as motor driver chips is proposed. The pump mode of the traditional circuit is changed based on the traditional charge pump, the output frequency of the oscillator is increased, and the capacitance area of the pump is reduced. The design and simulation of the proposed charge pump circuit are carried out based on HHG 0.35 um BCD technology. The simulation results show that when the simulation temperature is 27 °C and the clock cycle is set to 1 us, the voltageVin+5V can be stably output after 923 us, and the on-load current can reach 0.2 mA. The results meet the design requirements and provide a new way to solve this kind of problem.

A 4–5.2 GHz PLL with 74.8 fs RMS jitter in 28 nm for RF Sampling Transceiver application

AbstractThis paper presents a novel ultra low jitter phase‐locked loop (PLL) circuit architecture for RF Sampling Transceiver. The programmable frequency divider with duty cycle expansion and the new phase frequency detector and charge pump circuit are used to solve the problem of voltage domain conversion of narrow pulses in the traditional high‐performance charge pump PLL structure. The traditional structure degrades charge pump linearity and noise, thus deteriorating overall jitter performance. Furthermore, voltage‐controlled oscillator uses the dual core structure and the second harmonic suppression technology, combined with the proposed new switching capacitor structure, and achieves −139.3 dBc/Hz phase noise at the 1 MHz frequency offset of the 5.2 GHz carrier under the open loop state. The PLL implemented in a standard Taiwan Semiconductor Manufacturing Company 28 nm process occupies a core area of 0.4 mm2 and generates a frequency ranging from 4 to 5.2 GHz using 50 MHz oscillator input, the power consumption is 40 mW. It achieves 74.8 fs root‐mean‐square jitter integrated from 10 KHz to 30 MHz. When the PLL output is divided by 2, the output phase noise at 1 MHz frequency offset is −125.75 dBc/Hz, and the PLL FoM is −246.

Low‐powerFinFETbased boost converter design using dynamic threshold body biasing technique

AbstractThe recent development in the field of sustainable energy solution for ultra‐low power application is attracting the attention of researchers. This paper is themed on the boosting of input harvested voltage from micro thermo‐electric generator to an appropriate output voltage level. This research proposed an optimized DC–DC boost converter design comprising of cross‐coupled FinFET based LC resonant oscillator and FinFET three‐stage charge pump circuit. The design utilizes the dynamic threshold body biasing technique to control the threshold voltage of FinFET switches and enhance the performance in sub‐threshold region. This design succeeded in achieving 29.25% peak power conversion efficiency to generate 438 mV output voltage from 96 mV minimum input voltage while consuming 344 nW of power only. Further, the proposed boost converter shows peak voltage conversion efficiency of 53.51% and settling time of 121 μS for 1% band. The performance of proposed boost converter observed for rigorous process, temperature and load variations is within acceptable limits. In contrast to MOSFET technology, the adopted 18 nm FinFET technology make the proposed design excellent to tackle the challenges of short channel effects in ultra‐low power application.

Coupling charge pump and BUCK circuits to efficiently enhance the output performance of triboelectric nanogenerator

Triboelectric nanogenerator (TENG) faces significant challenges in practical applications because of its low output charge density and high matching impedance, and the development of its energy management circuits is hindered by high initial device requirements, large circuit size and poor portability. In this work, we propose a simple, efficient and versatile energy management strategy that two-stage amplification of TENG output performance by coupling a charge pump circuit with a BUCK circuit. By implementing the energy management strategy, the charge output per cycle of an ordinary TENG can be increased by more than 40 times, resulting in a power density of 25.2 mWm−2 and a total energy transfer efficiency of exceeding 88% in constant mode. At a working frequency of 1 Hz, the TENG can charge a 1000 μF capacitor to 5.04 V in 240 s and store the energy of more than 12.72 mJ, of which represents an 848-fold increase in stored energy compared to using TENG directly. Remarkably, this TENG device exhibits exceptional an average power of 100.7 μW/Hz, setting a new record for devices with smaller TENG size (< 50 cm2) or limited PM circuit size (< 10 cm2). Moreover, an ordinary TENG can continuously power a wireless sensor by integrating the portable power management circuit, facilitating real-time wireless data transmission. This study is of great significance for the practical application of the TENG power supply in the sensor network of the Internet of Things and for expanding the application range of the TENG.

A 13.56 MHz Low-Power, Single-Stage CMOS Voltage-Boosting Rectifier for Wirelessly Powered Biomedical Implants

In this paper, a low-power, single-stage, active rectifier based on a new charge-pump circuit is presented to be used in biomedical implants. The proposed circuit not only rectifies the AC input voltage to a DC voltage but also amplifies the DC output voltage to a higher level. Low-loss MOS switches are used in the structure of the designed circuit to provide high power conversion efficiency. In addition, by using two comparators, the reverse leakage current is somehow eliminated, resulting in a higher increase in the power efficiency. By tying the source and bulk terminals of the utilized transistors, the body effect problem has been solved, and by connecting the p-substrate to the ground, which is the lowest voltage in the circuit, the latch-up phenomenon is eliminated without any extra circuit. The proposed rectifier is implemented and post-layout simulated in a 0.18 µm standard CMOS technology. According to the simulation results, 1.205 V output DC voltage is achieved from an AC input signal with the peak-to-peak amplitude of 1 V at the operating frequency of 13.56 MHz with a 3 kΩ load resistance. The total active area of the designed circuit is 0.167 mm2 with a maximum power conversion efficiency of 98.2%, output power in the range of 0.5–1.5 mW, and voltage conversion ratio of 120%.

High-Performance Charge Pump Regulator with Integrated CMOS Voltage Sensing Control Circuit

This paper introduces a design for a charge pump DC-DC boost regulator with an integrated low-voltage control circuit. With a charge pump and feedback circuits implemented in 0.35 µm CMOS technology, the proposed DC-DC boost regulator offers an efficient device solution for low-power applications. The proposed design employs an error amplifier, oscillator, and comparator in the control circuit which is designed with a supply voltage of 1.8–3.5 V and 2 MHz frequency. Stability is obtained via a pole-zero compensation in the feedback circuit. The charge pump regulator with four pump stages and the whole regulator circuit are analyzed using the Cadence simulation tool. Measurements of the fabricated 0.35 µm CMOS regulator show that the transient time of the error amplifier is controlled within 1.0 µsec and the output voltage is accurately controlled from 7.8 V to 9.4 V with 27–38 mV ripple and 4.5 mA maximum current.

All-in-One SPAD Ranging Sensor With Real-Time Xtalk Calibration and Integrated Biasing

This letter presents a novel fully integrated dToF system-on-chip ranging sensor based on a SPADs array. The sensor is made a configurable array of 16 × 16 SPADs, a 940nm VCSEL, a co-design VCSEL driver and embedded DSP core. To suitable different ranging scenarios with high reliability and low cost, the above mentioned are all packaged into one module for ranging. However, the package of coverglass can cause Xtalk, which have a negative impact on ranging. In order to reduce the influence of Xtalk on ranging. This letter proposes a real-time Xtalk calibration circuit system, which can automatically adjust the laser pulse width, when Xtalk and target bins are mixed together. And also to mitigate the effect of SPAD jitter on the Xtalk bins width, an adjustable bias voltage charge pump circuit is adopted to realize the accurate adjustment of pixel SPAD’s bias voltage. The system has been turned out with precision of better than 5mm within 6m in 80% reflectance of target, still with a precision better than 8mm at a distance within 4m in 18% reflectance of target.

One-Dimensional Maximum Power Point Tracking Design of Switched-Capacitor Charge Pumps for Thermoelectric Energy Harvesting

This paper proposes a one-dimensional (1D) maximum power point tracking (MPPT) design which only requires measurement of one parameter (the input voltage of a switched-capacitor charge pump) for calibrating a power converter including the charge pump and thermoelectric generator. The frequency of the clock to drive the charge pump is designed to minimize the circuit area of the entire charge pump circuit for generating a target output current at a specific output voltage. The ratio of the capacitance value of each boosting capacitor (C) to the size of the switching MOSFET can be determined to maximize the transferring current at the same time. When a thermoelectric generator (TEG) is given, its output impedance is determined. Its open-circuit voltage varies with the temperature difference between two plates of the TEG. MPPT maximizes the output power of the charge pump even when the temperature difference varies. It was indicated that the number of stages of charge pump (N) needs to increase when the temperature difference lowers, whereas C needs to decrease inversely proportional to N, meaning that the C–N product should be kept unchanged for MPPT. Demonstration of the circuit design was conducted in 65 nm CMOS, and the measured results validated the concept of the 1D MPPT.

Design and Development of Microbial Fuel Cells Based Low Power Energy Harvesting Mechanism for Ecological Monitoring and Farming of Agricultural Applications

Energy harvesting from the microbial fuel cells have a significant attention in the recent days, due to their cost efficiency, simple designing structure and self-powered system. Also, the emergence of internet of things plays a vital role in many real time application scenarios like agricultural purposes and activities. But, the incorporation of these techniques is one of challenging and interesting tasks in the research field. In the conventional works, the internet of things has been utilized as a cloud storage domain for activating the sensors used for environmental monitoring and controlling purposes. The main intention of this paper is to design a robust and cost-effective sludge water based microbial fuel cells, and utilize it for an internet of things incorporated ecological monitoring and farming applications by activating the smart sensors. It discusses about the various electrode combination with several mixture of substrate to study about the optimum performance of microbial fuel cells. To ease the comparative study, Thing Speak platform is used along with the necessary sensors for continuous monitoring. In addition to that, the efficiency of single and dual chamber microbial fuel cell is analyzed based on the set of parameters such as cost, size, and construction. In this work, the microbial fuel cell-based energy harvesting scheme is also developed with switched capacitance-based metal oxide semiconductor field effect transistor and relay-based charge pump circuit which can be incorporated to the internet of things based agriculture applications. Here, the cost analysis of microbial fuel cell with and without DC–DC converter have been compared for selecting the most suitable one for the application system. Moreover, the digital temperature and humidity sensor can be utilized with the proposed microbial fuel cell system for gathering the inputs of the ecological system, which acts as an interface of the microbial fuel cell and cloud systems. During experimentation, the results of both the energy harvesting schemes are evaluated and compared by using various performance indicators.

Low-Voltage-Driven SnO2-Based H2S Microsensor with Optimized Micro-Heater for Portable Gas Sensor Applications.

To realize portable gas sensor applications, it is necessary to develop hydrogen sulfide (H2S) microsensors capable of operating at lower voltages with high response, good selectivity and stability, and fast response and recovery times. A gas sensor with a high operating voltage (>5 V) is not suitable for portable applications because it demands additional circuitry, such as a charge pump circuit (supply voltage of common circuits is approximately 1.8–5 V). Among H2S microsensor components, that is, the substrate, sensing area, electrode, and micro-heater, the proper design of the micro-heater is particularly important, owing to the role of thermal energy in ensuring the efficient detection of H2S. This study proposes and develops tin (IV)-oxide (SnO2)-based H2S microsensors with different geometrically designed embedded micro-heaters. The proposed micro-heaters affect the operating temperature of the H2S sensors, and the micro-heater with a rectangular mesh pattern exhibits superior heating performance at a relatively low operating voltage (3–4 V) compared to those with line (5–7 V) and rectangular patterns (3–5 V). Moreover, utilizing a micro-heater with a rectangular mesh pattern, the fabricated SnO2-based H2S microsensor was driven at a low operating voltage and offered good detection capability at a low H2S concentration (0–10 ppm), with a quick response (<51 s) and recovery time (<101 s).

A 5 V-to-32 V Input PVT-Robust Charge-Pump Circuit with Adjustable Output in a 0.18 μm BCD Process

In this paper, a new closed-loop charge-pump circuit with adjustable output voltage and an on-chip compensation technique is proposed. The environmental temperature and process corner can be detected with an on-chip detection circuit and automatically feedback an adjusted reference voltage. With this, the magnitude of the charge-pump output voltage with Pulse-Width Modulation (PWM) can be compensated. The charge-pump circuit is designed and verified with a 180 nm Bipolar-CMOS-DMOS (BCD) process, and its output voltage at different process, voltage, and temperature (PVT) is controllable with low ripple. There are three selections for adjusting the output voltage: +5 V/+7 V/+10 V shifts, with the supply voltage ranging from 5 V to 32 V. It can remain tunable and stable at any shifts. The maximum deviation is ±0.265%, and the maximum load current can reach 30 mA. The ripple voltage is less than 0.3% (Δ Vripple/Vout) underthe maximum load. The Monte Carlo simulation results show that the worst case of the process sensitivity (σ/μ) is 0.1%. The charge-pump core area is 0.308 mm2, and the power consumption is 4.753 mW. The circuit can produce high-precision output and is suitable for high-side driving IC applications.

Generation performance of self-biased dielectric elastomer generator based on charge pump circuit

In order to study the power generation characteristics of a self-biased dielectric elastomer generator (DEG), a charge pump circuit applied to a DEG was designed based on the charge pump principle after analyzing the structure and power generation mechanism of DEG. A self-biased DEG model was established in MATLAB/Simulink software. The model was simulated and the factors on the output voltage of DEG, such as the series and capacitance of the charge pump circuit, were studied. Furthermore, the corresponding test platform was built. Then, the comparative analysis between the test results and simulation results was studied. The test and simulation results show that the combination of the charge pump circuit and DEG could realize the function of self-biased power generation. The larger the charge pump series, the higher the output voltage of DEG. The test study found that the output voltage of DEG was higher when the charge pump series was 3. The larger the capacitance of the charge pump, the lower the output voltage of DEG. When the capacitance of the charge pump was too large, the boosted voltage of DEG was not obvious. However, if the input voltage was low, the output voltage of DEG was high when the charge pump capacitance value was large. The above results provide the basis for further study of the self-biased DEG.

A low noise 5.12 GHz PLL ASIC in 55 nm for NICA multi purpose detector project

This paper presents the design and the test results of a low noise PLL ASIC for the optical data transmission system in NICA MPD project. In the proposed PLL, a novel charge pump circuit uses two feedback operational amplifiers to obtain low leakage current and reduce dynamic mismatch. A LC-VCO circuit combines the two-step capacitor tuning structure and the novel capacitor array unit to obtain a reasonable frequency range and an optimized Q factor performance. The PLL ASIC has been fabricated in a 55 nm CMOS process. The test results show that the PLL ASIC outputs the 5.12 GHz clock with a phase noise of −108 dBc/Hz at 1 MHz offset and a rms jitter of 880 fs. The PLL core consumes 22.2 mW from a 1.2 V power supply.

Design of Miniaturized Incident Angle-Insensitive 2.45 GHz RF-Based Energy Harvesting System for IoT Applications

Using a license-free industrial, scientific, and medical (ISM) frequency band as 2.45 GHz, a miniaturized incident angle-insensitive radio frequency (RF) energy harvester design for the Internet-of-Things (IoT) applications is proposed. For incident angle insensitivity of ambient RF energy and a low-profile compact design, the proposed harvester is used to a two-layer printed circuit board (PCB) substrate, which consists of orthogonally deployed antennas with an <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$LC$ </tex-math></inline-formula> balun, impedance matching, and Dickson charge pump circuits at each layer. The dual-polarized antenna for miniaturized design uses a bowtie-shaped meander dipole antenna having orthogonal arrangement. By measuring the efficiency of each diode stage of the rectifier circuit, a two-stage Dickson charge pump circuit with optimal efficiency was selected, and the dc outputs of the two rectifier circuits are connected in parallel. This rectifier circuit has a conversion efficiency of up to 71.4% and harvests approximately 1.6 times more power than a single-polarized circuit from any incident ambient RF signal. Due to its compact size and improved harvesting power at various incident angles, the proposed energy harvester can act as a power source, such as many kinds of ultralow power consumption systems, such as IoT sensors and medical applications.

Charge Pump Using Gain-Boosting and Positive Feedback Techniques in 180-nm Digital CMOS Process

The charge pump (CP) circuit is an essential element in a delay-locked loop (DLL). This paper proposes a new CP using gain-boosting technique. Two possible solutions for gain-boosting circuit implementation are presented. One solution is based on common-source amplifier. In another solution, positive feedback method is employed at the output stage to increase the output resistance of the amplifier. Therefore, DC-gain of the amplifier is improved. In addition, nonlinear current mirror is employed in which the gain is dependent to the input current. To evaluate the performance of the proposed CPs, simulations are done in a 0.18 μm CMOS process with the supply voltage of 1.8 V. The simulation results indicate that the proposed CPs can obtain good current matching characteristics in the low power applications. The mismatch between up and down CP currents is less than 1%.