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Many electronic systems require one or more negative supply rails, typically implemented alongside corresponding positive rails to form symmetrical power supplies. These negative voltages are essential for proper biasing, signal swing, and device operation in various applications, including gate-driver circuits for EV power electronics. This enables efficient switching of wide-bandgap semiconductors such as gallium-nitride (GaN) FETs and silicon-carbide (SiC) MOSFETs in onboard chargers (OBCs) and traction inverters.

Precision analog front ends (AFEs), including high-resolution analog-to-digital converters (ADCs) and digital-to-analog converters (DACs), require negative rails to deliver a full dynamic range and linearity in industrial and medical equipment. Rail-to-rail op amps used in many of the same signal chains need negative supply voltages for the same reason. Medical imaging equipment depends on negative voltages for detector bias and signal conditioning.