| The abilities of human that dealing with a variety of social activities become more and more effective due to the rapidly development of electronic technologies and communication devices. And a power module, with high reliability, low power consumption and excellent performance, is the basic requirement of overall electronic systems. Power module is one of the essential core parts of electric machines, and now it is possible to integrate all kinds of circuits to a chip because of the rapidly development of micro electronics technology worldwide. Compare to a huge power module of a electric system, an integrated power chip gains more advantages such as lower consumption, higher convert efficiency, smaller dimension, stronger drive ability and higher reliabilityThis article focuses on modeling research as well as reliability of sub-module circuit of peak current model Buck Switching Converter. The research work contains these aspects as listed below:Analysis on the basic topology and theory of Switching Converter. Through the research on theories of Switching Converter, the main current types of Switching Converter are analyses. The main analysis includes the types of power stage switching loop circuit, the models of control loop circuit and the methods of sample control. And the brief conclusion is that,in order to gain more performance on input adjustment rate, load adjustment rate and transfer rate, the modeling should focus on Switching Converter that formed by peak current control mode,PWM mode and continuous conduction modeModeling of peak current model buck Switching Converter. Through theoretical arithmetic, a model in time domain is built by Simulink and a model in frequency domain is built by Matlab. Analysis the result of modeling simulation and propose the method of control loop. The main work contains switching loop modeling, control loop modeling and system modeling. And the switching loop modeling is made up of non-ideal parameter equivalence, large signal model, research hypothesis, small signal model and transfer function extraction of it. The control loop modeling is made up of voltage loop sampling, error amplifier, current loop sampling, slope compensation and transfer function extraction of it. The system modeling including an analysis on frequency stability of system when control loop is closed.Verify the correctness of the model. Verify the model using Matlab, including frequency domain validation using Matlab and time domain validation using Simulink. Analysis the factors of instability in voltage loop and current loop respectively, then propose a frequency compensate method in voltage loop and a slope compensate method in current loop. The result of stability simulation shows that this compensate method enables the system work more stable and gains more abilities on load adjustment rate as well as on input adjustment rate. Confirm each module base on the built model, and then determine sub-module’s performance parameter. The result of system simulation validates the correctness of the model, and verifies the reliable relationship of mapping from system model to sub-circuit.Validate the reliability of core sub-circuit. According to the confirmed parameter of sub-circuit, design the sub-circuit using IC design software Cadence-IC5141 and verify its reliability. Bring about the mapping relationship from system circuit model to sub circuit model. Sub-module circuits contain OP amplifier, voltage comparer, voltage reference, slope compensate circuit and oscillator. This article accomplish the first validation through system modeling mapping to system design, and then accomplish the second validation through system design mapping to the design of sub-module circuit.The result of the simulation shows that system model can totally cover all systematic performance parameters of Switching Converter, and the systematic performance parameters can all be achieved by sub-circuit, thus validates the significance of the model to practice project. |
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