SLVS913E January   2009  – January 2016 DRV8823

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 Electrical Characteristics
    6. 6.6 Timing Requirements
    7. 6.7 Dissipation Ratings
    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 PWM Motor Drivers
    4. 7.4 Device Functional Modes
      1. 7.4.1 Bridge Control
      2. 7.4.2 Current Regulation
      3. 7.4.3 Blanking Time
      4. 7.4.4 Decay Mode
      5. 7.4.5 Protection Circuits
        1. 7.4.5.1 OCP
        2. 7.4.5.2 Thermal Shutdown (TSD)
        3. 7.4.5.3 Undervoltage Lockout (UVLO)
        4. 7.4.5.4 Shoot-Through Current Prevention
      6. 7.4.6 Serial Data Transmission
      7. 7.4.7 Data Format
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Motor Voltage
      3. 8.2.3 Drive Current
      4. 8.2.4 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Thermal Considerations
      1. 10.3.1 Power Dissipation
      2. 10.3.2 Heatsinking
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

8 Application and Implementation

NOTE

Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.

8.1 Application Information

The DRV8823 can be used to drive two bipolar stepper motors.

8.2 Typical Application

DRV8823 typ_app_slvs913.gif Figure 14. Typical Application Schematic

8.2.1 Design Requirements

Table 5 shows the design parameters.

Table 5. Design Parameters

DESIGN PARAMETER REFERENCE EXAMPLE VALUE
Supply voltage VM 24 V
Motor winding resistance RL 7.4 Ω/phase
Motor full step angle θstep 1.8°/step
Target microstepping angle nm 1/8 step
Target motor speed V 120 rpm
Target full-scale current IFS 1 A

8.2.2 Detailed Design Procedure

8.2.2.1 Motor Voltage

The appropriate motor voltage will depend on the ratings of the motor selected and the desired torque. A higher voltage shortens the current rise time in the coils of the stepper motor allowing a greater average torque. Using a higher voltage also allows the motor to operate at a faster speed than a lower voltage.

8.2.3 Drive Current

The current path running to the motor starts from the supply VM, then goes through the high-side sourcing NMOS power FET, moves through the inductive winding load of the motor, then through the low-side sinking NMOS power FET, and finally going through the external sense resistor. Power dissipation losses in both NMOS power FETs inside of the DRV8823 are shown in the following equation: Equation 2.

Equation 2. P = I2 × (RDS (on) × 2)

The DRV8823 has been measured to be capable of 1.5-A continuous current with the HTSSOP package at 25°C on standard FR-4 PCBs. The max continuous current varies based on PCB design and the ambient temperature.

8.2.4 Application Curves

DRV8823 SLOWDECAY_HALFSTEP.png Figure 15. ½ Step Microstepping With Slow Decay
DRV8823 MIXEDDECAY_HALFSTEP.png Figure 17. ½ Step Microstepping With Mixed Decay
DRV8823 SLOWDECAY_EIGHTH_STEP.png Figure 16. 1/8 Step Microstepping With Slow Decay
DRV8823 MIXEDDECAY_EIGHTHSTEP.png Figure 18. 1/8 Step Microstepping With Mixed Decay