TIDUF36A May   2023  – December 2023 DRV8328

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Key System Specifications
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
    3. 2.3 Highlighted Products
      1. 2.3.1 DRV8328C
      2. 2.3.2 MSPM0G1507
      3. 2.3.3 CSD18510Q5B
      4. 2.3.4 TMP61
  9. 3System Design Theory
    1. 3.1 Power Stage Design: Three-Phase Inverter
      1. 3.1.1 Selecting Sense Resistor
    2. 3.2 Power Stage Design: DRV8328 Gate Driver
      1. 3.2.1 DRV8328 Features
      2. 3.2.2 AVDD Linear Voltage Regulator (LDO)
    3. 3.3 Power Stage Design: MSPM0 Microcontroller
      1. 3.3.1 Low-Side Current Sensing With MSPM0G1507
      2. 3.3.2 Temperature Sensing
    4. 3.4 Power Stage Design: External Interface Options and Indications
      1. 3.4.1 Hall Sensor Interface
      2. 3.4.2 Input Power Voltage Monitoring
      3. 3.4.3 Motor Speed Control
      4. 3.4.4 Direction of Rotation: Digital Input
      5. 3.4.5 Programming Interface for MCU
      6. 3.4.6 Data Transmission
      7. 3.4.7 LED Indicators
      8. 3.4.8 Sleep Mode Entry Control
  10. 4Hardware, Software, Testing Requirements, and Test Results
    1. 4.1 Hardware Requirements
      1. 4.1.1 Hardware Board Overview
    2. 4.2 Software Requirements
    3. 4.3 Test Setup
    4. 4.4 Test Results
      1. 4.4.1 Functional Evaluation of DRV8328 Gate Driver
        1. 4.4.1.1 DRV8328 Linear Regulator Performance
        2. 4.4.1.2 Gate Drive Voltage Generated by Gate Driver
      2. 4.4.2 MOSFET Switching Waveforms
      3. 4.4.3 Current Open Loop Test
      4. 4.4.4 Current Open Loop Load Test
  11. 5Design and Documentation Support
    1. 5.1 Design Files
      1. 5.1.1 Schematics
      2. 5.1.2 BOM
    2. 5.2 Tools and Software
    3. 5.3 Documentation Support
    4. 5.4 Support Resources
    5. 5.5 Trademarks
  12. 6About the Author
  13. 7Revision History

1 System Description

Power tools are used in various industrial and household applications such as drilling, grinding, cutting, polishing, driving fasteners, and so forth. The most common types of power tools use electric motors while some use internal combustion engines, steam engines, or compressed air. Power tools can be either corded or cordless (battery powered). Corded power tools use the mains power (the grid power) to power up the AC or DC motors.

Cordless tools use battery power to drive DC motors. Most cordless tools use lithium-ion batteries, the most advanced in the industry offering high energy density, low weight, and greater life. Power tools are available in different power levels and battery voltage levels. Power tools such as cordless chainsaws and circular saws and different garden tools like cordless wood and branch cutters require a very high torque and need a very high peak current.

Cordless tools use brushed or brushless DC (BLDC) motors. The BLDC motors are more efficient and have less maintenance, low noise, and longer life. Power tools have requirements on form factor, efficiency, peak current, reliability, and thermal performance. Therefore, high-efficient power stages with a compact size are required to drive the power tool motor. The small form factor of the power stage enables flexible mounting, better PCB layout performance, and low-cost design. High efficiency provides maximum battery duration and reduces cooling efforts. The high-efficiency requirement in turn demands switching devices with a low drain-to-source resistance (RDS(on)). The power stage must also make sure protections like motor stall or any high current prevention are available.

This reference design uses the CSD18510Q5B MOSFET featuring a very low RDS(on) of 0.79-mΩ in a SON5 × 6 SMD package. The DRV8328C three-phase gate driver is used to drive the three-phase MOSFET bridge, which can operate from 4.5 V to 60 V and support programmable gate current with a maximum setting of 2-A sink and 1-A source. The DRV8328C includes low dropout (LDO), which helps to provide power for the MCU. The TPM61 temperature sensor is used to sense the FET temperature. The MSPM0G1506 microcontroller is used to implement the control algorithm.