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

10.3 Thermal Considerations

The thermally enhanced package provided with the DRV8332 is designed to interface directly to heat sink using a thermal interface compound in between, (that is, Ceramique from Arctic Silver, TIMTronics 413, and so on). The heat sink then absorbs heat from the ICs and couples it to the local air. It is also a good practice to connect the heatsink to system ground on the PCB board to reduce the ground noise.

RθJA is a system thermal resistance from junction to ambient air. As such, it is a system parameter with the following components:

  • RθJC (the thermal resistance from junction to case, or in this example the power pad or heat slug)
  • Thermal grease thermal resistance
  • Heat sink thermal resistance

The thermal grease thermal resistance can be calculated from the exposed power pad or heat slug area and the thermal grease manufacturer's area thermal resistance (expressed in °C-in2/W or °C-mm2/W). The approximate exposed heat slug size is as follows:

  • DRV8332, 36-pin PSOP3 …… 0.124 in2 (80 mm2)

The thermal resistance of a thermal pad is considered higher than a thin thermal grease layer and is not recommended. Thermal tape has an even higher thermal resistance and should not be used at all. Heat sink thermal resistance is predicted by the heat sink vendor, modeled using a continuous flow dynamics (CFD) model, or measured.

Thus the system RθJA = RθJC + thermal grease resistance + heat sink resistance.

See the TI application report, IC Package Thermal Metrics (SPRA953), for more thermal information.