Current BMS HV monitoring designs use discrete implementations of the voltage divider circuit – resistors, switches, and op amps are individually soldered onto the PCB. However, these designs have a handful of issues.

Due to creepage and clearance requirements, these resistor chains can become quite long to put a sufficient physical distance between the high-voltage node and low-voltage node. This takes up more space on the board. Since the resistors are not all of the same type, they have different tolerances and can demonstrate significant temperature/lifetime drift, lowering ratio precision. In addition, exposed nodes of the discrete components provide a potential source of leakage or parasitic capacitance or inductance that can reduce the accuracy of the overall measurement. Vulnerability of the nodes to contamination can also harm precision or shorten the lifespan of the parts. The price associated with discrete designs must account for the cost of resistors, switches, and op amps (voltage buffers) as well as cost of board space and assembly expenses. This compounds with each HV measurement unit, increasing overall cost and BOM complexity.