Reference Design Board from ams for 48 Volt Lithium Battery Monitoring Systems

ams AG has launched a reference board for a small, high-performance and simple 48 V automotive battery monitoring system. The board is suitable for use in the next generation of single 48 V lithium battery systems, and in dual 48 V/12 V battery systems, such as those used in passenger and light commercial vehicles and electric scooters and motorbikes.

The ams 48 V 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 board’s high-side current sensor is connected to the battery’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 battery’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 individuell cells and switches the charge and discharge current between cells in order to maintain an equal voltage across all cells.

Because the entire 48 V battery monitoring system operates without complex application software, it is easy to implement in a vehicle’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.

‘The new battery monitoring reference board from ams shows that 48 V 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 48 V battery monitoring systems,” said Sabine Jud, marketing manager in the mobility sensors product line of ams.

The 48 V battery monitoring system reference design board is available on request from ams via its ICdirect online store.

For further information on the 48V reference design board, please visit