Reference Design for 48V Automotive Li Battery Systems
ams AG today launched a reference board for a small, high-performance and simple 48V automotive battery monitoring system. The board is suitable for use in the next generation of single 48V lithium battery systems, and in dual 48V/12V battery systems, such as those used in passenger and light commercial vehicles and electric scooters and motorbikes.
The ams 48V board provides a complete battery monitoring and safety system on a single, compact PCB. It measures the flow of current through the battery, and the voltage and temperature both of the entire battery and of individual lithium cells.
The boardâ€™s high-side current sensor is connected to the batteryâ€™s positive terminal. This has enabled ams to include a battery disconnect switch on the board which is automatically actuated when the current sensor detects an overload condition. This protects the batteryâ€™s cells from damage and helps to prolong the life of the battery.
The ams board also implements an innovative method of cell balancing in hardware, without the intervention of a microcontroller or processor. The board compares the voltages of individual cells and switches the charge and discharge current between cells in order to maintain an equal voltage across all cells.
Because the entire 48V battery monitoring system operates without complex application software, it is quick and easy to implement in a vehicleâ€™s power management system. It also makes it easier for power system designers to achieve compliance with the ISO 26262 functional safety standard, because it eliminates the need to develop, test and verify the safe functioning of complex algorithms for error compensation and cell balancing.
â€œThe new battery monitoring reference board from ams shows that 48V power systems in vehicles do not have to be complex or difficult to implement. The high performance of the ams board is due to the precision and accuracy of its analog components and on-board 48V precision attenuator. This means that it can do without the complex error compensation software and high-end microcontroller required by other 48V battery monitoring systems,â€ said Sabine Jud, marketing manager in the mobility sensors product line of ams.