Design And Realization Of A High Precision Load Current Sharing Controller

With the rapid development of informatization,a large number of communication devices,servers,workstations,etc.are widely used,which requires a safe and reliable large-capacity power system to provide uninterrupted power supply.If a single power supply is used,high requirements are placed on the output power and long-term reliability of the power supply,and once a failure occurs,the entire system will collapse.To achieve high power output,using multiple power modules in parallel is a development direction of power management technology.Load sharing controller,as a power control integrated circuit,has a wide range of applications in distributed power systems.By controlling multiple parallel power supply modules to achieve current sharing power supply,each power supply module only needs to output a balanced output with lower power,which improves the stability of the power supply system and solves the problems faced by a single power supply.This thesis proposes the design and implementation of a load current sharing controller based on the maximum current automatic current sharing method according to actual needs by researching and analyzing the current current sharing method.Combined with the user’s index requirements and the type of device used in the circuit,the chip in this subject is designed using the BCD technology.Comprehensive consideration from the aspects of circuit,layout,module and system makes better results in terms of accuracy,power dissipation,driving and speed,and finally achieves a high-precision load current sharing controller with low offset(offset voltage≤100μV)and low current sharing error(current sharing error≤5%).The thesis focuses on the in-depth discussion and research of the circuit module units and the overall layout of the circuit.The optimization design of the circuit,combined with the use requirements of the product and the ambient temperature for comprehensive simulation verification makes the circuit design meeting the user requirements.The layout design process adopts the fully customized layout design process of Cadence software,and is designed according to the design rules and corresponding design rule files provided by the foundry.By optimizing the driving capacity,power dissipation and current density in the layout,artificial layout and wiring intervention,grounding isolation and channel isolation are adopted to reduce the noiseand crosstalk caused by the large current.At the same time,the matching design is adopted to improve the stability of the device.The risk of chip tape-out is greatly reduced by the consideration of various factors in the design process and the resolution of key issues,and the chip index meets the design index requirements and meets the user’s use requirements by the test and verification of the tape-out chip in this thesis.The successful development of the product has accumulated valuable experience for the load current sharing control module and analog mixed signal circuit core,and will also solve the problem of the scarcity of high precision and low mismatch load current sharing controllers currently on the market,and will bring a good economy to the company interest.