SLES242G December   2009  – December 2014 DRV8412 , DRV8432

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
    1.     Simplified Application Diagram
  4. Revision History
  5. Pin Configuration and Functions
    1.     Pin Functions
  6. Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Package Heat Dissipation Ratings
    6. 6.6 Package Power Deratings (DRV8412)
    7. 6.7 Electrical Characteristics
    8. 6.8 Typical Characteristics
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Error Reporting
      2. 7.3.2 Device Protection System
        1. 7.3.2.1 Bootstrap Capacitor Undervoltage Protection
        2. 7.3.2.2 Overcurrent (OC) Protection
        3. 7.3.2.3 Overtemperature Protection
        4. 7.3.2.4 Undervoltage Protection (UVP) and Power-On Reset (POR)
      3. 7.3.3 Device Reset
    4. 7.4 Device Functional Modes
  8. Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Full Bridge Mode Operation
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Motor Voltage
          2. 8.2.1.2.2 Current Requirement of 12-V Power Supply
          3. 8.2.1.2.3 Voltage of Decoupling Capacitor
          4. 8.2.1.2.4 Overcurrent Threshold
          5. 8.2.1.2.5 Sense Resistor
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Parallel Full Bridge Mode Operation
      3. 8.2.3 Stepper Motor Operation
      4. 8.2.4 TEC Driver
      5. 8.2.5 LED Lighting Driver
  9. Power Supply Recommendations
    1. 9.1 Bulk Capacitance
    2. 9.2 Power Supplies
    3. 9.3 System Power-Up and Power-Down Sequence
      1. 9.3.1 Powering Up
      2. 9.3.2 Powering Down
    4. 9.4 System Design Recommendations
      1. 9.4.1 VREG Pin
      2. 9.4.2 VDD Pin
      3. 9.4.3 OTW Pin
      4. 9.4.4 Mode Select Pin
      5. 9.4.5 Parallel Mode Operation
      6. 9.4.6 TEC Driver Application
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 PCB Material Recommendation
      2. 10.1.2 Ground Plane
      3. 10.1.3 Decoupling Capacitor
      4. 10.1.4 AGND
    2. 10.2 Layout Example
      1. 10.2.1 Current Shunt Resistor
    3. 10.3 Thermal Considerations
      1. 10.3.1 DRV8412 Thermal Via Design Recommendation
  11. 11Device and Documentation Support
    1. 11.1 Related Links
    2. 11.2 Trademarks
    3. 11.3 Electrostatic Discharge Caution
    4. 11.4 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

Bulk Capacitance

Having an appropriate local bulk capacitance is an important factor in motor drive system design. It is generally beneficial to have more bulk capacitance, while the disadvantages are increased cost and physical size.

The amount of local capacitance needed depends on a variety of factors, including:

  • The highest current required by the motor system
  • The power supply’s capacitance and ability to source current
  • The amount of parasitic inductance between the power supply and motor system
  • The acceptable voltage ripple
  • The type of motor used (Brushed DC, Brushless DC, Stepper)
  • The motor braking method

The inductance between the power supply and the motor drive system limits the rate current can change from the power supply. If the local bulk capacitance is too small, the system responds to excessive current demands or dumps from the motor with a change in voltage. When adequate bulk capacitance is used, the motor voltage remains stable and high current can be quickly supplied.

The data sheet generally provides a recommended value, but system-level testing is required to determine the appropriate sized bulk capacitor.

DRV8412 DRV8432 power_supply_rec.gifFigure 19. Example Setup of Motor Drive System With External Power Supply

The voltage rating for bulk capacitors should be higher than the operating voltage, to provide margin for cases when the motor transfers energy to the supply.