The digital-to-analogue converter （DAC） plays a significant role in modern electronic systems, and current-mode DACs are widely used due to their excellent properties. However, the non-ideal transition at switching ...The digital-to-analogue converter （DAC） plays a significant role in modern electronic systems, and current-mode DACs are widely used due to their excellent properties. However, the non-ideal transition at switching instants of the unit circuit will directly affect the performance of the current-mode DAC. The parasitic effects resulting in non-ideal transition are analyzed in this paper. A simple structure unit circuit is proposed to diminish the non-ideal transition. The simulation results show that the parasitic effects are suppressed effectively, and a smoother output transition is achieved. The feasibility of the proposed current-mode DAC unit circuit is verified by the application in a frequency jitter circuit.展开更多
In this research, a fast methodology to calculate the exact value of the average dynamic power consumption for CMOS combinational logic circuits is developed. The delay model used is the unit-delay model where all gat...In this research, a fast methodology to calculate the exact value of the average dynamic power consumption for CMOS combinational logic circuits is developed. The delay model used is the unit-delay model where all gates have the same propagation delay. The main advantages of this method over other techniques are its accuracy, as it is deterministic and it requires less computational effort compared to exhaustive simulation approaches. The methodology uses the Logic Pictures concept for obtaining the nodes’ toggle rates. The proposed method is applied to well-known circuits and the results are compared to exhaustive simulation and Monte Carlosimulation methods.展开更多
The high working junction temperature of power component is the most common reason of its failure. So the thermal design is of vital importance in electronic control unit （ECU） design. By means of circuit simulation...The high working junction temperature of power component is the most common reason of its failure. So the thermal design is of vital importance in electronic control unit （ECU） design. By means of circuit simulation, the thermal design of ECU for electronic unit pump （EUP） fuel system is applied. The power dissipation model of each power component in the ECU is created and simulated. According to the analyses of simulation results, the factors which affect the power dissipation of components are analyzed. Then the ways for reducing the power dissipation of power components are carried out. The power dissipation of power components at different engine state is calculated and analyzed. The maximal power dissipation of each power component in all possible engine state is also carried out based on these simulations. A cooling system is designed based on these studies. The tests show that the maximum total power dissipation of ECU drops from 43.2 W to 33.84 W after these simulations and optimizations. These applications of simulations in thermal design of ECU can greatly increase the quality of the design, save the design cost and shorten design time展开更多
随着新环境保护法的实施以及国内环保要求的不断提高,作为炼油厂环保装置的核心环节的硫磺联合装置,如何在长周期中保持平稳运行的问题受到炼油厂的重视,也是目前石油化工企业环保生产的必要保障。本文根据GB/T 30579及API RP 571对某...随着新环境保护法的实施以及国内环保要求的不断提高,作为炼油厂环保装置的核心环节的硫磺联合装置,如何在长周期中保持平稳运行的问题受到炼油厂的重视,也是目前石油化工企业环保生产的必要保障。本文根据GB/T 30579及API RP 571对某石化公司硫磺联合装置包括的硫磺回收装置、溶剂再生装置、酸性水汽提装置依据现有实际工艺流程进行腐蚀机理的识别、腐蚀回路分析,并对回路进行腐蚀风险评估,同时结合案例分析预测每个腐蚀回路中的重点监控部位及建议。展开更多
基金Project supported by the National Natural Science Foundation of China(No.61401243)the Scientific Research Foundation of Ningbo University,China(No.xkl1331)
文摘The digital-to-analogue converter （DAC） plays a significant role in modern electronic systems, and current-mode DACs are widely used due to their excellent properties. However, the non-ideal transition at switching instants of the unit circuit will directly affect the performance of the current-mode DAC. The parasitic effects resulting in non-ideal transition are analyzed in this paper. A simple structure unit circuit is proposed to diminish the non-ideal transition. The simulation results show that the parasitic effects are suppressed effectively, and a smoother output transition is achieved. The feasibility of the proposed current-mode DAC unit circuit is verified by the application in a frequency jitter circuit.
文摘In this research, a fast methodology to calculate the exact value of the average dynamic power consumption for CMOS combinational logic circuits is developed. The delay model used is the unit-delay model where all gates have the same propagation delay. The main advantages of this method over other techniques are its accuracy, as it is deterministic and it requires less computational effort compared to exhaustive simulation approaches. The methodology uses the Logic Pictures concept for obtaining the nodes’ toggle rates. The proposed method is applied to well-known circuits and the results are compared to exhaustive simulation and Monte Carlosimulation methods.
文摘The high working junction temperature of power component is the most common reason of its failure. So the thermal design is of vital importance in electronic control unit （ECU） design. By means of circuit simulation, the thermal design of ECU for electronic unit pump （EUP） fuel system is applied. The power dissipation model of each power component in the ECU is created and simulated. According to the analyses of simulation results, the factors which affect the power dissipation of components are analyzed. Then the ways for reducing the power dissipation of power components are carried out. The power dissipation of power components at different engine state is calculated and analyzed. The maximal power dissipation of each power component in all possible engine state is also carried out based on these simulations. A cooling system is designed based on these studies. The tests show that the maximum total power dissipation of ECU drops from 43.2 W to 33.84 W after these simulations and optimizations. These applications of simulations in thermal design of ECU can greatly increase the quality of the design, save the design cost and shorten design time
文摘随着新环境保护法的实施以及国内环保要求的不断提高,作为炼油厂环保装置的核心环节的硫磺联合装置,如何在长周期中保持平稳运行的问题受到炼油厂的重视,也是目前石油化工企业环保生产的必要保障。本文根据GB/T 30579及API RP 571对某石化公司硫磺联合装置包括的硫磺回收装置、溶剂再生装置、酸性水汽提装置依据现有实际工艺流程进行腐蚀机理的识别、腐蚀回路分析,并对回路进行腐蚀风险评估,同时结合案例分析预测每个腐蚀回路中的重点监控部位及建议。
