SLUAAP4 October   2023 LM2005 , LM2101 , LM2103 , LM2104 , LM2105 , LM5108 , UCC27301A , UCC27311A , UCC27531 , UCC27710 , UCC44273

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Gate Driver IC Configurations
  6. 3Key Voltage and Current Specifications
    1. 3.1 Voltage Ratings
    2. 3.2 Peak Current
  7. 4Robustness Features
    1. 4.1 Undervoltage Lockout
    2. 4.2 Negative Voltage Handling
    3. 4.3 Cross-Conduction Protection
  8. 5Board Space, Thermal Performance, and Other Considerations
  9. 6Summary
  10. 7References

Voltage Ratings

The supply voltage (VDD) 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 VDD 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 (VGS) of these switches. Some systems require a lower VDD 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 VDD to avoid violating key voltage specifications like VHB–VHS. So, before finalizing driver selection, check the recommended operating conditions table in the device’s data sheet to verify the selected VDD 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 VHS and VHB.

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 VHS 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.