SLES256F May   2010  – May 2022 DRV8312 , DRV8332

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 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 Dissipation Ratings
    6. 6.6 Power Deratings (DRV8312)
    7. 6.7 Electrical Characteristics
    8. 6.8 Typical Characteristics
  7. 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
          1. 7.3.2.1.1 Overcurrent (OC) Protection
        2. 7.3.2.2 Overtemperature Protection
        3. 7.3.2.3 Undervoltage Protection (UVP) and Power-On Reset (POR)
        4. 7.3.2.4 Device Reset
    4. 7.4 Device Functional Modes
      1. 7.4.1 Different Operational Modes
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Three-Phase 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
          6. 8.2.1.2.6 Output Inductor Selection
        3. 8.2.1.3 Application Curves
      2. 8.2.2 DRV8312 Application Diagram for Three-Phase Operation
      3. 8.2.3 Control Signal Logic With Conventional 6 PWM Input Scheme
      4. 8.2.4 Hall Sensor Control With 6 Steps Trapezoidal Scheme
      5. 8.2.5 Sensorless Control With 6 Steps Trapezoidal Scheme
  9. 9 Power Supply Recommendations
    1. 9.1 Bulk Capacitance
    2. 9.2 System Power-Up and Power-Down Sequence
      1. 9.2.1 Powering Up
      2. 9.2.2 Powering Down
    3. 9.3 System Design Recommendations
      1. 9.3.1 VREG Pin
      2. 9.3.2 VDD Pin
      3. 9.3.3 OTW Pin
      4. 9.3.4 FAULT Pin
      5. 9.3.5 OC_ADJ Pin
      6. 9.3.6 PWM_X and RESET_X Pins
      7. 9.3.7 Mode Select Pins
  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
        1. 10.2.1.1 66
    3. 10.3 Thermal Considerations
      1. 10.3.1 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

9.1 Bulk Capacitance

Having 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 motor drive system will limit the rate current can change from the power supply. If the local bulk capacitance is too small, the system will respond 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 datasheet generally provides a recommended value, but system-level testing is required to determine the appropriate sized bulk capacitor.

GUID-1DBF4F05-42C2-41C4-A37A-60F961875C94-low.gifFigure 9-1 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.