Research And Design Of A Dual-Channel High-Side Smart Power Switch Circuit

With the development and progress of semiconductor manufacturing technology,un-der the trend of electrification,automation,and IT in automobiles,large-scale electronic control systems are widely used in automotive electronics,aerospace,industrial control.The intelligent power switch in power integrated circuits integrates the main power transis-tor,driving circuit,protection circuit,state detection,and state feedback circuit on a single chip.With its advantages of easy driving,high reliability,and small size,it is in line with the current trend of intelligent,miniaturized,and highly integrated electronic control sys-tems.The research on high side intelligent power switches is of great significance.This thesis proposes a dual channel high-side intelligent power switch,the internal supply and state feedback circuits are shared by channel 1 and channel 2,and the dual chan-nel drive and protection circuits are symmetrically arranged.The typical operating voltage of this high-side intelligent power switch is 12V,and it can operate within the power sup-ply voltage range of 6V～28V.The operating temperature range is-40℃～175℃.It has a standby mode function,complete protection functions,and precise multi target sampling and feedback functions.It can drive resistive loads,inductive loads,capacitive loads,and special types of loads that generate inrush currents.Firstly,this thesis analyzes how the dual channel high-side intelligent power switch works,describes the overall architecture of chip and the functions of each sub-module briefly,and clarifies the design indicators of the high-side intelligent power switch.Sec-ondly,the analysis and design of each submodule of the chip were carried out,and simu-lation verification was conducted.The submodule mainly includes four modules:internal power supply,drive circuit,protection circuit,status detection and feedback circuit.The internal power supply mainly includes a reference voltage source,linear regulator sources,an auxiliary power supply,and its logic control signals.The drive circuit mainly includes a charge pump and gate drive circuit,and the protection circuit includes overvoltage,overcurrent,and overtemperature protection circuits.The state detection circuit includes open load detection circuit,current sampling circuit,supply voltage detection circuit,and temperature detection circuit.After that,the overall simulation of the chip was carried out,including switching between standby mode and working mode,driving resistive load on/off simulation,driving inductive load on/off simulation,and load short circuit simula-tion.When driving a resistive load of 6Ωwith a single channel on-resistance of 153mΩat room temperature,the turn-on delay time is approximately 45μs,turn-on(d V_OUT/dt)_onis about 0.09V/μs.The turn-off delay time is approximately 75μs,turn-off(d V_OUT/dt)_offis approximately 0.11V/μs.The simulation results meet the design index requirements.Finally,some external circuits of the high-side intelligent power switch are analyzed and designed,including three power supply reverse connection protection schemes,driving in-ductive load power supply voltage power failure protection schemes,and load open circuit detection external pull-up resistance designs.