Based on the analysis of the basic principle of slope compensation, a high-precision adaptive slope compensation circuit for peak current mode boost DC/DC converter is designed. The circuit dynamically detects the inp...Based on the analysis of the basic principle of slope compensation, a high-precision adaptive slope compensation circuit for peak current mode boost DC/DC converter is designed. The circuit dynamically detects the input and output voltage of the boost circuit to realize automatic adjustment of the compensation amount with the change of duty ratio, which makes the ramp compensation slope optimized. The design uses a high-precision subtracter to improve the accuracy of slope compensation. While eliminating sub-slope oscillation and improving the stability of boost circuit, the negative impact of compensation on boost circuit is minimized, and the load capacity and transient response speed of boost circuit are guaranteed. The circuit is designed based on SMIC 0.18um CMOS technology, with simple structure, high reliability and easy engineering implementation. Spectre circuit simulator 17.1.0.124 64b simulation results show that the circuit has high compensation accuracy and wide input and output voltage range. When the working voltage is 3.3 V, the compensation slope can be adjusted adaptively under different duty cycles, and the minimum error between the compensation slope and the theoretical optimal compensation slope is only 0.42%.展开更多
Bifurcation and chaos in high-frequency peak current mode Buck converter working in continuous conduction mode（CCM） are studied in this paper. First of all, the two-dimensional discrete mapping model is established....Bifurcation and chaos in high-frequency peak current mode Buck converter working in continuous conduction mode（CCM） are studied in this paper. First of all, the two-dimensional discrete mapping model is established. Next, reference current at the period-doubling point and the border of inductor current are derived. Then, the bifurcation diagrams are drawn with the aid of MATLAB. Meanwhile, circuit simulations are executed with PSIM, and time domain waveforms as well as phase portraits in i_L–v_C plane are plotted with MATLAB on the basis of simulation data. After that, we construct the Jacobian matrix and analyze the stability of the system based on the roots of characteristic equations. Finally, the validity of theoretical analysis has been verified by circuit testing. The simulation and experimental results show that,with the increase of reference current I_（ref）, the corresponding switching frequency f is approaching to low-frequency stage continuously when the period-doubling bifurcation happens, leading to the converter tending to be unstable. With the increase of f, the corresponding Irefdecreases when the period-doubling bifurcation occurs, indicating the stable working range of the system becomes smaller.展开更多
A new cycle-by-cycle control flyback converter with primary side detection and peak current mode control is proposed and its dynamic characteristics are analyzed. The flyback converter is verified by the OrCAD simulat...A new cycle-by-cycle control flyback converter with primary side detection and peak current mode control is proposed and its dynamic characteristics are analyzed. The flyback converter is verified by the OrCAD simulator. The main advantages of this converter over the conventional one are simplicity, small size, rapid regulating and no sensing control signals over the isolation barrier. The circuit is suitable for digital control implementations.展开更多
Threshold current characteristics of intracavity-contacted oxide-confined vertical-cavity surface-emitting laser had been investigated in detail. Threshold current characteristics not only were depended on the size of...Threshold current characteristics of intracavity-contacted oxide-confined vertical-cavity surface-emitting laser had been investigated in detail. Threshold current characteristics not only were depended on the size of oxide-aperture, but also were also strongly affected by the mismatch of its lasing mode and gain peak. For the same degree detuning of the gain peak and lasing mode at room temperature, the threshold current was approximately proportional to the square of the oxide-aperture diameter of above 5μm. For the same oxide-aperture device, the larger the detuning degree of the lasing mode shifted to the shorter wavelength of the gain peak at room temperature was, the lower the minimum threshold current was. The wavelengths of the lasing mode and gain peak were ±N×10nm detuning at 300K, The temperature of the minimum threshold current was changed to be about ±N×40K(N real number). The calculated results were consistent with the experimental ones.展开更多
文摘Based on the analysis of the basic principle of slope compensation, a high-precision adaptive slope compensation circuit for peak current mode boost DC/DC converter is designed. The circuit dynamically detects the input and output voltage of the boost circuit to realize automatic adjustment of the compensation amount with the change of duty ratio, which makes the ramp compensation slope optimized. The design uses a high-precision subtracter to improve the accuracy of slope compensation. While eliminating sub-slope oscillation and improving the stability of boost circuit, the negative impact of compensation on boost circuit is minimized, and the load capacity and transient response speed of boost circuit are guaranteed. The circuit is designed based on SMIC 0.18um CMOS technology, with simple structure, high reliability and easy engineering implementation. Spectre circuit simulator 17.1.0.124 64b simulation results show that the circuit has high compensation accuracy and wide input and output voltage range. When the working voltage is 3.3 V, the compensation slope can be adjusted adaptively under different duty cycles, and the minimum error between the compensation slope and the theoretical optimal compensation slope is only 0.42%.
基金Project supported by the National Natural Science Foundation of China(Grant No.61376029)the Fundamental Research Funds for the Central Universities,Chinathe College Graduate Research and Innovation Program of Jiangsu Province,China(Grant No.SJLX15 0092)
文摘Bifurcation and chaos in high-frequency peak current mode Buck converter working in continuous conduction mode（CCM） are studied in this paper. First of all, the two-dimensional discrete mapping model is established. Next, reference current at the period-doubling point and the border of inductor current are derived. Then, the bifurcation diagrams are drawn with the aid of MATLAB. Meanwhile, circuit simulations are executed with PSIM, and time domain waveforms as well as phase portraits in i_L–v_C plane are plotted with MATLAB on the basis of simulation data. After that, we construct the Jacobian matrix and analyze the stability of the system based on the roots of characteristic equations. Finally, the validity of theoretical analysis has been verified by circuit testing. The simulation and experimental results show that,with the increase of reference current I_（ref）, the corresponding switching frequency f is approaching to low-frequency stage continuously when the period-doubling bifurcation happens, leading to the converter tending to be unstable. With the increase of f, the corresponding Irefdecreases when the period-doubling bifurcation occurs, indicating the stable working range of the system becomes smaller.
文摘A new cycle-by-cycle control flyback converter with primary side detection and peak current mode control is proposed and its dynamic characteristics are analyzed. The flyback converter is verified by the OrCAD simulator. The main advantages of this converter over the conventional one are simplicity, small size, rapid regulating and no sensing control signals over the isolation barrier. The circuit is suitable for digital control implementations.
基金National Natural Science Foundation of China ( 60276033 ) National High Technology Research and Development Program of china(2002AA312070)+1 种基金 National Key Basic Research Plan of china(G20000683-02) Beijing Natural Science Foundation of China
文摘Threshold current characteristics of intracavity-contacted oxide-confined vertical-cavity surface-emitting laser had been investigated in detail. Threshold current characteristics not only were depended on the size of oxide-aperture, but also were also strongly affected by the mismatch of its lasing mode and gain peak. For the same degree detuning of the gain peak and lasing mode at room temperature, the threshold current was approximately proportional to the square of the oxide-aperture diameter of above 5μm. For the same oxide-aperture device, the larger the detuning degree of the lasing mode shifted to the shorter wavelength of the gain peak at room temperature was, the lower the minimum threshold current was. The wavelengths of the lasing mode and gain peak were ±N×10nm detuning at 300K, The temperature of the minimum threshold current was changed to be about ±N×40K(N real number). The calculated results were consistent with the experimental ones.
