SLVAFZ0 November   2024 DRV8161 , DRV8162

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Three-Phase Gate Driver
    1. 2.1 Architecture
    2. 2.2 Layout Considerations
      1. 2.2.1 Advantages
        1. 2.2.1.1 MCU to DRV Signal Routing
        2. 2.2.1.2 Component Reduction
      2. 2.2.2 Challenges
        1. 2.2.2.1 MOSFET Placement
    3. 2.3 Typical Applications
  6. 3Half-Bridge (Single Phase) Gate Driver
    1. 3.1 Architecture
    2. 3.2 Layout Considerations
      1. 3.2.1 Advantages
        1. 3.2.1.1 MOSFET Placement
        2. 3.2.1.2 Independent Control
        3. 3.2.1.3 Ease of Replacement
      2. 3.2.2 Challenges
        1. 3.2.2.1 Longer Routing Between Gate Driver and Micro Controller
        2. 3.2.2.2 Additional Component Requirements
    3. 3.3 Typical Applications
  7. 4Summary
  8. 5References

3.2.2.2 Additional Component Requirements

The single half-bridge gate driver being used to drive a three-phase BLDC motor often requires more passive components compared to a similar three-phase gate driver.

The decoupling capacitors used for charge pump, GVDD and VDRAIN can be needed for each of the half-bridge driver compared to being only being needed once for a three-phase drive.

The same logic applies for passive resistors used for device configurations set modes such as IDRIVE, VDS level, deadtime, and so on. This adds to the implementation cost of single half-bridge drivers in return for the customization offered with this architecture.

Table 3-1 shows the extra passive components that can be required in a 3x half-bridge system as opposed to three-phase system. Note that the passive resistors are not needed on devices with SPI.

Table 3-1 Passive Component Differences Between Three-Phase and 3x Half-Bridge Gate Driver BLDC Implementation
PassivePINThree-Phase3x Half Bridge Driver
CapacitorGVDD13
VDRAIN13
CSAREF13
ResistorIDRIVE13
VDS level13
Deadtime13
CSA Gain13
nFault13
3x Single Half Bridge Driver Showing Reduction in Gate Inductance and Layout BenefitsFigure 3-4 3x Single Half Bridge Driver Showing Reduction in Gate Inductance and Layout Benefits