| With the rapid development of integrated circuit technology,switching power supplies are widely used in power supply systems of various electronic devices due to their high efficiency,miniaturization,and fast response speed.However,for some lowvoltage and high-current power supply fields,such as industrial robot arms,supercomputer server systems,solid-state radar transmitters,etc.,due to the limited power capacity and switching stress of ordinary single power supply,the multi-phase interleaved parallel technology should be transported.Born.The technology is appropriately combined into a distributed power management system through multiple small-capacity power supplies,which can have a wide load output range,and has high working efficiency regardless of light load and heavy load,and parallel system of multiple power supplies.It can also alleviate the switching stress and heat dissipation of the large current output of a single switch.Based on the topology of Buck-type DC-DC converter,this paper designs a stepdown DC converter with multi-phase interleaving and parallel high current.The converter adopts PWM modulation mode and has good linear adjustment rate and load adjustment.rate.The innovation of the converter is digital control based on the analog modulation loop,which not only utilizes the control method of the peak current mode in the analog system,but also enables the converter to respond quickly and stably to changes in the input voltage and output load.Using the digital phase-locked loop technology,the phase difference of the n-phase power supply operating clock is sequentially,the total output current is n times the output current of a single chip,and the whole system analog circuit and digital circuit are organically combined to realize low ripple high current output.This paper focuses on the working principle and advantages of multi-phase interleaved parallel technology,which can greatly alleviate the stress of components and reduce the ripple of output voltage and output current.In parallel operation,it is necessary to adopt a reasonable current sharing technology to prevent the modules from being burnt due to uneven current stress and local heating of the chip.Based on the modeling analysis of current mode control,the loop compensation of the two-phase parallel system is carried out,and the simulation of the system loop is carried out by SIMPLIS software to prove the feasibility of the scheme.In this paper,the error amplifier and phase-locked loop key module are designed.The gain of the error amplifier determines the gain of the loop to a great extent.The phase-locked loop system can realize the frequency-locked phaselocking function.Based on the HHGrace 0.18?m BCD process,the single-phase power supply and multi-phase interleaved parallel system are simulated and verified by HSPICE software.The output voltage is stable at 1.8V,and the single phase works well regardless of light and heavy load,and according to the load stage.The simulation result of the jump is 0.27%,the circuit can respond quickly and stably;the output currents of the two-phase,three-phase and four-phase parallel systems are 14 A,21A,28 A,respectively,and the output frequency is single-phase 2,3,respectively.4 times,the output voltage ripple is 1.48 mV,720?V,648?V,respectively.The output voltage ripple is much lower than the single-phase 6.76 mV,and the operating frequency is 94.16%,94.14%,94.15%,respectively.The interleaved parallel system circuit It has the advantages of wide load,high efficiency,low voltage and high current output,and has achieved the expected requirements. |
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