48 V Battery Management System (BMS)

48 V batteries tend to be created using Li-ion multi-cell battery packs using 8-16 cells. From a safety perspective, but also to ensure the best efficiency and longest battery life these battery packs need to be carefully monitored and controlled. This requires accurate voltage, temperature and current as well as battery state of charge (SoC) and state of health (SoH) monitoring. In addition for most efficient battery use, good cell balancing and battery optimization is a must.

Block diagram
Design considerations
Product listing
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Block diagram

Highlighted components are Nexperia focus products.

Charge balancing MOSFETs

Zener diodes

Autosense translators

Analog switch

ESD protection

e-fuse / regulation

Buck converter

Related sub-systems (1)

Step-down DC/DC converter

MCU core supply

Related sub-systems (1)

DC/DC conversion for MCU core supply

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To view more information about the Nexperia components used in this application, please select a component above or click on a component (highlighted in blue) in the block diagram.

Design considerations

Depending on the current being drawn some systems can use internal cell balancing topologies, but where there is a higher current then external MOSFETs are recommended.
Engineers also have a choice between passive and active cell balancing, although active cell balancing is often more complex give, its need for charge storage elements
Zener diodes utilized in the cell balancing stage protect the FETs and battery cell

Product listing

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