To address the limitations of conventional opamp-free bandgap reference architectures—specifically their high temperature coefficient and insufficient power supply rejection ratio(PSRR)performance,which fail to meet high-precision application requirements—a high-PSRR bandgap reference circuit with segmented curvature compensation was designed. The proposed bandgap reference circuit adopts a voltage self-regulation structure,which suppresses power supply ripple in the low-frequency range through a negative feedback loop and enhances the anti-interference capability of the output voltage. Furthermore,a PTAT2(proportional to absolute temperature squared)compensation circuit was integrated to generate a compensation current,enabling segmented curvature compensation and thus realizing a significant reduction in the temperature coefficient. The proposed bandgap reference circuit was designed based on the SMIC 0.18 μm CMOS process. Simulation results indicate that,at an operating voltage of 3.3V,the bandgap reference output voltage is 1.197V;over the temperature range of-45 ℃ to 125 ℃,the temperature coefficient is 5.38×10-6/℃. The PSRR of this bandgap reference at low frequencies reaches-103dB,and the circuit has a quiescent current of 14.8 μA.
Three-dimensional inductors,owing to their small footprint,low loss,and high inductance,are widely applied in MEMS sensors,RF MEMS,and energy storage systems. Traditional three-dimensional MEMS inductors rely on high aspect ratio pillars for support and are typically fabricated by UV-LIGA lithography or through-silicon-via(TSV)technology,resulting in a complex process. To simplify the fabrication,this paper presented a MEMS-based method for three-dimensional arch inductor supported by a non-photosensitive polyimide layer. The inductor employed a high-permeability,Co-based amorphous alloy wire as the magnetic core,significantly enhancing its electrical performance. By optimizing development time to improve the smoothness of polyimide sidewalls,an arch coil was fabricated without high aspect ratio pillars,thus simplifying the process and enhancing device stability. The fabricated MEMS arch inductor achieves an inductance of 1881nH at 78.5MHz,with its electrical performance variation within 3% over the temperature range from 20℃ to 120 ℃.
With the continuous development of tactile sensing technology,the application of piezoelectric materials in tactile sensors has garnered increasing attention. Currently,tactile sensors face challenges such as low recognition accuracy,insufficient response sensitivity,and poor stability in complex environments. To address these issues,research was conducted on utilizing the piezoelectric properties of polyvinylidene difluoride(PVDF)to convert external force signals into electrical signals for sensor design. Additionally,a microcontroller was utilized for real-time acquisition and storage of data collected by tactile sensors. At the same time,the improved Back Propagation(BP)neural network was combined withParticle Swarm Optimization(PSO)to enhance signal processing and recognition capabilities. The sensitivity and response accuracy of the sensor were significantly improved through the design of a PVDF multilayer structure. The results show that the classification performance(accuracy 98.54%,recall 98.13%,F1 value 97.42%)is significantly better than that of the comparison algorithm,and the highest recognition accuracy of the sensor for different roughness and hardness items reaches 95% and 96%,respectively,with a maximum root mean square error(RMSE)of only 0.032.In summary,the design of a PVDF piezoelectric film and single-chip tactile sensor based on the improved BP has effectively improved the response accuracy of tactile sensors under different tactile stimuli,with high perceptual sensitivity and stability. This further promotes the application and development of intelligent robots in precision operations and complex tasks.
A bandgap reference voltage source(BGR)adopting a composite compensation method was designed. Based on the Banba-type bandgap reference topology,an additional BJT branch and compensation resistors were utilized to cancel the high-order effects of the base-emitter voltage(V). A piecewise compensation circuit was also incorporated to achieve curvature compensation over a wide temperature range. Meanwhile,a digital trimming circuit was employed to further reduce the impact of process variations on circuit performance. Designed in the SMIC 180nm BCD process,post-layout simulation results showed that the reference source could stably output a voltage of 800mV with a temperature coefficient of 0.98×10/℃over the temperature range of-40-150℃. When the supply voltage varied from 1V to 3.3V,the output drift was 5.4mV,with a line regulation of less than 0.23%.
Piezoelectric inkjet printing technology is widely employed in various fields,including 3D printing,electronics manufacturing,and biomedical applications,owing to its advantages such as high precision,low noise,and borad material adaptability. The driving power supply is a critical component of piezoelectric inkjet systems,as the driving pulse waveform it applies to the piezoelectric ceramics determines the quality of the inkjet-printed products. However,existing driving power supplies face challenges such as generating only unipolar voltage waveforms and exhibiting poor compatibility,making it difficult to meet the personalized requirements of different types of piezoelectric printheads for driving signals. To address these issues,an adjustable high-voltage driving power supply circuit based on an FPGA chip was designed. The proposed circuit incorporates a polarity conversion module to switch the polarity of the driving waveform and a two-stage amplification circuit combining amplifiers and transistor amplifiers to achieve voltage amplification. Additionally,control code was developed and simulations were conducted to validate the effectiveness of the driving power supply. The proposed circuit not only facilitates the generation and amplification of low-voltage pulse signals but also successfully outputs bipolar trapezoidal waves with adjustable gain. Simulation results demonstrate that the driving power supply can generate adjustable bipolar pulse signals with a rise time of 20 μs,a voltage amplitude of±170V,and a frequency of 4.17kHz. Furthermore,it supports the simultaneous operation of multiple nozzles under a 2nF load condition.
To meet the high demands of 500-kW electromagnetic propulsion systems on pulse power supplies in terms of energy density,conversion efficiency,and output stability,this paper presented a pulse power supply design based on a hybrid energy storage system combining supercapacitors and film capacitors. The power supply employed supercapacitor banks for energy storage and film capacitor banks for instantaneous high-power discharge. An efficient discharge topology ensured stable power transmission to the load module,while a three-level protection mechanism enhanced the safety and reliability of the discharge process. Experimental results indicate that the prototype achieves an energy density of 18.3Wh/kg,and a conversion efficiency of 91.74%. The pulse current overshoot is controlled within 5.00%. All these metrics satisfy the technical requirements of 500-kW class electromagnetic propulsion systems. The proposed pulse power supply effectively addresses issues such as low energy density,poor conversion efficiency,and insufficient load adaptability in existing medium-power electromagnetic propulsion pulse power supplies.
To address the limitations of traditional quality management methods in processing and analyzing massive data for electronic components,this study aims to establish an intelligent quality monitoring mechanism for enhancing the accuracy and reliability of quality assessment. A novel dual-model framework integrating quality monitoring and fault prediction was established using the whole-life-cycle multi-source data: 1)A quality assessment model employing hyperparameter-optimized machine learning algorithms was constructed,utilizing six-dimensional feature data covering factory inspection,in-process quality assurance,and defect records;2)A fault prediction model was designed based on a backpropagation(BP)neural network to enable dynamic early warnings. Experimental validation on JZC-084 electromagnetic relays and J599F26D low-frequency connectors demonstrated that the proposed method achieved a fault prediction error rate lower than 0.1% and a quality assessment accuracy of 95.1%,which exceeded technical specifications. Verification via the random forest classifier showed average precision,recall,and F1-score values of 83.6%,81.2%,and 78.3%,respectively. This data-driven approach significantly enhances scientific decision-making in quality management through real-time monitoring and cross-departmental data synergy. Future work will focus on model parameter optimization and scenario expansion to enhance prediction comprehensiveness.
Biaxially oriented polypropylene(BOPP)exhibits superior energy conversion efficiency and remarkable power density. However,its inherently low dielectric constant fundamentally limits its energy storage capacity,thereby impeding its applications in power storage systems,smart manufacturing,and aerospace engineering. In this study,oxygen plasma treatment was systematically employed to modify the surface of BOPP films,which effectively increased the number of oxygen-containing functional groups on the film surface and enhanced its hydrophilicity. Subsequently,the electrical properties of the modified BOPP films were comprehensively characterized,and the influence of plasma treatment time on these properties was quantitatively investigated. The results indicate that with the extension of plasma treatment time,the dielectric constant of BOPP films increased monotonically from 2.20 to 2.37.When the treatment time was 5min,the breakdown strength and discharge energy density of the modified films reached 785.7MV·m-1 and 6.78J·cm-3,respectively. This work provides a feasible and novel strategy for the development of dielectric films with high energy storage performance,laying a foundation for their broader application in the advanced energy storage scenarios.
The limited energy density of supercapacitors poses significant constraints on their practical applications. To address this issue,in this study,the hydrothermal method was used to grow an anthracene-based covalent organic framework(DaTp-COF)in-situ on the surface of graphene oxide(GO),and a novel DaTp/rGO composite electrode material was prepared. The structure,morphology,and electrochemical properties of the material were systematically characterized. The results reveal that the DaTp/rGO composite possesses a unique hierarchical porous structure with micropores,mesopores,and macropores. Meanwhile,the electron-withdrawing effect of the anthracene groups in the structure induces apseudocapacitive response of the Schiff base groups. Benefiting from this,in a three-electrode system with a 0.5mol·L-1 sulfuric acid electrolyte,the specific capacitance of DaTp/rGO electrode reaches 251F·g-1 at a current density of 1A·g-1,which is significantly higher than that of rGO electrode material. In the ionic liquid electrolyte system,the DaTp/rGO electrode only exhibits the characteristics of electric double layer capacitance. However,owing to its excellent hierarchical pore structure,the electrode's specific capacitance is still as high as 158F·g-1 at a current density of 1A·g-1,and the capacitance retention rate is 78.82% after 10000 cycles. This study used the in-situ growth method to achieve the synergy between DaTp-COF and rGO,providing new ideas for the research and development of high-performance supercapacitor electrode materials,and helping supercapacitors break through their application limitations.
To address the temperature gradient requirements for low-temperature soldering and high-temperature service,variable-temperature solders were developed,and the regulatory effects of Ni particle content on their properties and those of brazed joints were clarified. Using 4#SAC305solder powder as the base material,2-5 μm Ni particles and HP01high-activity flux were compounded to prepare Ni-based variable temperature solder paste. The effects of Ni content on the melting characteristics and wettability of the solder paste,as well as the growth of intermetallic compounds(IMCs)at the brazed joint interface and changes in shear strength during aging,were investigated. The results show that when the Ni content is 10%,the solder's melting point can rise to 227 ℃,with only a marginal increase observed after high-temperature storage. Wettability initially enhanced and subsequently decreased as the Ni content increased,resulting in a 60% reduction in the spread area observed at 20% Ni. The growth of the interfacial IMC layer corresponds well with the square root of the aging duration,achieving a thickness of 37.611 μm after 360hours of aging at 20% Ni. Under the same Ni content,shear strength decreases with prolonged aging,and under the same aging condition,it decreases with increasing Ni content. The solder paste with 10% Ni exhibitsminimal impact on shear strength due to aging,and its fracture surface displays a mixed ductile-brittle characteristic. The variable-temperature solder with 10% Ni content demonstrates the best overall performance,effectively raises the solder's melting point while exhibiting excellent stability during high-temperature service,thereby meeting the requirements for temperature gradient applications.