The Design Of A Constant High-side Power Supply Circuit For Intelligent Power Drivers

Intelligent power drivers have been widely applied in many industrial fields such as domestic appliances,automotive electronics and industrial control,due to the advantages of high integration and high reliability.The bootstrap circuit is the most commonly used and convenient HV-side power supply circuit in intelligent power drivers,but it cannot supply constantly which limits the working frequency of the intelligent power driver and may affect its further development and application.The refresh circuit is an effective way to solve the problem of long-term power supply on the high-voltage side at this stage.but the switching process of the load device during the refresh will introduce additional switching losses.As a result,it is of great significance to development of a novel HV-side power supply structure in replacement of refreshing circuits.Firstly,the application background of intelligent power drivers and the basic theory of traditional bootstrap power supply technology is introduced.After that it focuses on the research and analysis of the mechanism of the traditional HVside constant power supply structures,pointing out that the limitations of these structures are the complexity of the circuit,large voltage difference losses,and long HV-side start time.A novel half-bridge embedded HV-side power supply circuit which contains a control signal generating circuit,an internal bootstrap charge pump circuit and a power supply control circuit is improved and designed to overcome the inconstancy of traditional power supply and realize the effect of dynamic and constantly power supply for the HV-side of the intelligent power drivers by using a second level bootstrap circuit to charge and discharge the bootstrap capacitor repeatedly,reducing the difference losses by voltage compensation.The design of this thesis is based on the 600 V SOI process platform for post simulation.The simulation results reveals that,the HV-side of the intelligent power driver get dynamic power supplied constantly,at the same time it has a voltage difference loss of 0.2V and a 25.90μs HV-side start time,which is basically in agreement with the design indexes.