The supply voltage (V_DD) is important to consider for both half-bridge and low-side drivers. This specification is primarily tied to the power switch. In addition to general flexibility, a wide V_DD range (for example, UCC27531: 10 V to 32 V) is an appropriate choice for SiC MOSFETs or IGBTs as the range provides greater margin on the gate driver output for the high gate-source voltage (V_GS) of these switches. Some systems require a lower V_DD operation so that the gate driver output is compatible with power switches like Si MOSFETs or GaN (for example, UCC27517: 4.5 V to 18 V).

In half-bridge driver circuits, it’s also important to consider the V_DD to avoid violating key voltage specifications like V_HB–V_HS. So, before finalizing driver selection, check the recommended operating conditions table in the device’s data sheet to verify the selected V_DD does not yield a violation in specifications.

In addition to the half-bridge driver’s specifications, the other key voltage to consider is the system’s bus voltage. This voltage, along with how much headroom makes sense for the system, informs the required V_HS and V_HB.

Common bus voltages for DC motor drive systems range from 12 V to 110 V (DC). Typically, systems use components rated 50–100% higher than the bus voltage. For example, for a 48-V system, a driver with 100-V or 120-V V_HS voltage typically provides adequate margin against transients. Systems with well-controlled noise often do not need as much headroom. In other cases, designers prefer to utilize drivers with increased margin rather than minimizing layout noise.