SLVAFG1 September   2022 DRV8329

 

  1.   Abstract
  2.   Trademarks
  3. 1DRV8329 Key Features
  4. 2Power Tool Requirements
    1. 2.1 Performance
    2. 2.2 Robustness
    3. 2.3 Scalability
      1. 2.3.1 Battery Pack Quality
      2. 2.3.2 Battery Pack Voltage
  5. 3Summary

Performance

Power tools should have sufficient performance from no load to maximum load conditions. For instance, an 18-V cordless power drill in a no-load condition may spin at high speeds (up to 2000 RPM) while torque remains minimal. At a maximum load condition, the power drill may spin at very slow speeds or stall while supplying high torque (up to 1200 lb-in). Regardless of the load conditions, the Brushless-DC motor needs to deliver the required power to the mechanical load by commutating the motor with a sufficient Brushless-DC gate driver and power stage.

Figure 2-1 High-Performance Cordless Power Drill

Because the Brushless-DC motor in a power tool can deliver kilowatts of power, the power stage is designed to deliver up to several hundred amps of current. This requires using N-type power MOSFETs that have large gate-to-drain charges (QGD), continuous drain current ratings (ID), and voltage overhead for motor transients (VDS). In order to drive six power MOSFETs or 12 parallel MOSFETs, the DRV8329 reliably supports at least 10-V of gate-to-source voltage across 2S to 10S operating range to fully saturate the MOSFETs with up to 1-A peak source and 2-A peak sink gate currents. Additionally, the DRV8329 provides 100% duty cycle support to efficiently switch motor current and deliver large amounts of power to the BLDC motor.