A high precision voltage reference circuit for battery management system chip of new energy electric vehicle

This paper presents a High Precision Voltage Reference (HPVR) circuit used in high-precision battery parameter acquisition chip for Battery Management System (BMS) for new energy vehicles.It consists of a temperature sensing module, digital code generator or look up table (LUT), PTAT and constant current generators, core bandgap voltage reference circuit and low drop out (LDO) circuit with curvature compensation capability.The HPVR circuit has been designed in ASMC’s 0.5um HV60 BCD automotive electronics technology process. Post layout simulation result shows it can reach a temperature coefficient of 2.44ppm/℃ in -40 to 125 degrees Celsius according to automotive electronics requirement.After tape-out experimental results reveal that the temperature coefficient is less than 10ppm/℃ in the mentioned temperature range and can provide high precision 3V voltage and up to 20mA loading current.