SLOSE98A December   2022  – September 2023 DRV8461

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Pin Configuration and Functions
  7. 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
      1. 6.5.1 SPI Timing Requirements
      2. 6.5.2 STEP and DIR Timing Requirements
    6. 6.6 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Interface of Operation
      2. 7.3.2  Stepper Motor Driver Current Ratings
        1. 7.3.2.1 Peak Current Rating
        2. 7.3.2.2 RMS Current Rating
        3. 7.3.2.3 Full-Scale Current Rating
      3. 7.3.3  PWM Motor Drivers
      4. 7.3.4  Microstepping Indexer
      5. 7.3.5  Indexer Output
        1. 7.3.5.1 nHOME Output
      6. 7.3.6  Automatic Microstepping Mode
      7. 7.3.7  Custom Microstepping Table
      8. 7.3.8  Current Regulation
        1. 7.3.8.1 Internal Reference Voltage
      9. 7.3.9  Standstill Power Saving Mode
      10. 7.3.10 Current Regulation Decay Modes
        1. 7.3.10.1 Slow Decay
        2. 7.3.10.2 Mixed Decay
        3. 7.3.10.3 Smart tune Dynamic Decay
        4. 7.3.10.4 Smart tune Ripple Control
        5. 7.3.10.5 PWM OFF Time
        6. 7.3.10.6 Current Regulation Blanking Time and Deglitch Time
      11. 7.3.11 Current Sensing with External Resistor
      12. 7.3.12 Silent step decay mode
      13. 7.3.13 Auto-torque Dynamic Current Adjustment
        1. 7.3.13.1 Auto-torque Learning Routine
        2. 7.3.13.2 Current Control Loop
        3. 7.3.13.3 PD Control Loop
      14. 7.3.14 Charge Pump
      15. 7.3.15 Linear Voltage Regulator
      16. 7.3.16 VCC Voltage Supply
      17. 7.3.17 Logic Level, Tri-Level and Quad-Level Pin Diagrams
      18. 7.3.18 Spread Spectrum
      19. 7.3.19 Protection Circuits
        1. 7.3.19.1  VM Undervoltage Lockout
        2. 7.3.19.2  VCP Undervoltage Lockout (CPUV)
        3. 7.3.19.3  Logic Supply Power on Reset (POR)
        4. 7.3.19.4  Overcurrent Protection (OCP)
          1. 7.3.19.4.1 Latched Shutdown
          2. 7.3.19.4.2 Automatic Retry
        5. 7.3.19.5  Stall Detection
        6. 7.3.19.6  Open-Load Detection (OL)
        7. 7.3.19.7  Overtemperature Warning (OTW)
        8. 7.3.19.8  Thermal Shutdown (OTSD)
          1. 7.3.19.8.1 Latched Shutdown
          2. 7.3.19.8.2 Automatic Retry
        9. 7.3.19.9  Supply voltage sensing
        10. 7.3.19.10 nFAULT Output
        11. 7.3.19.11 Fault Condition Summary
      20. 7.3.20 Device Functional Modes
        1. 7.3.20.1 Sleep Mode
        2. 7.3.20.2 Disable Mode
        3. 7.3.20.3 Operating Mode
        4. 7.3.20.4 nSLEEP Reset Pulse
        5. 7.3.20.5 Functional Modes Summary
    4. 7.4 Programming
      1. 7.4.1 Serial Peripheral Interface (SPI) Communication
        1. 7.4.1.1 SPI Format
        2. 7.4.1.2 SPI for Multiple Target Devices in Daisy Chain Configuration
        3. 7.4.1.3 SPI for Multiple Target Devices in Parallel Configuration
    5. 7.5 Register Maps
      1. 7.5.1 Status Registers
        1. 7.5.1.1 FAULT (address = 0x00) [Default = 00h]
        2. 7.5.1.2 DIAG1 (address = 0x01) [Default = 00h]
        3. 7.5.1.3 DIAG2 (address = 0x02) [Default = 00h]
        4. 7.5.1.4 DIAG3 (address = 0x03) [Default = 00h]
      2. 7.5.2 Control Registers
        1. 7.5.2.1  CTRL1 (address = 0x04) [Default = 0Fh]
        2. 7.5.2.2  CTRL2 (address = 0x05) [Default = 06h]
        3. 7.5.2.3  CTRL3 (address = 0x06) [Default = 38h]
        4. 7.5.2.4  CTRL4 (address = 0x07) [Default = 49h]
        5. 7.5.2.5  CTRL5 (address = 0x08) [Default = 03h]
        6. 7.5.2.6  CTRL6 (address = 0x09) [Default = 20h]
        7. 7.5.2.7  CTRL7 (address = 0x0A) [Default = FFh]
        8. 7.5.2.8  CTRL8 (address = 0x0B) [Default = 0Fh]
        9. 7.5.2.9  CTRL9 (address = 0x0C) [Default = 10h]
        10. 7.5.2.10 CTRL10 (address = 0x0D) [Default = 80h]
        11. 7.5.2.11 CTRL11 (address = 0x0E) [Default = FFh]
        12. 7.5.2.12 CTRL12 (address = 0x0F) [Default = 20h]
        13. 7.5.2.13 CTRL13 (address = 0x10) [Default = 10h]
        14. 7.5.2.14 CTRL14 (address = 0x3C) [Default = 58h]
      3. 7.5.3 Indexer Registers
        1. 7.5.3.1 INDEX1 (address = 0x11) [Default = 80h]
        2. 7.5.3.2 INDEX2 (address = 0x12) [Default = 80h]
        3. 7.5.3.3 INDEX3 (address = 0x13) [Default = 80h]
        4. 7.5.3.4 INDEX4 (address = 0x14) [Default = 82h]
        5. 7.5.3.5 INDEX5 (address = 0x15) [Default = B5h]
      4. 7.5.4 Custom Microstepping Registers
        1. 7.5.4.1 CUSTOM_CTRL1 (address = 0x16) [Default = 00h]
        2. 7.5.4.2 CUSTOM_CTRL2 (address = 0x17) [Default = 00h]
        3. 7.5.4.3 CUSTOM_CTRL3 (address = 0x18) [Default = 00h]
        4. 7.5.4.4 CUSTOM_CTRL4 (address = 0x19) [Default = 00h]
        5. 7.5.4.5 CUSTOM_CTRL5 (address = 0x1A) [Default = 00h]
        6. 7.5.4.6 CUSTOM_CTRL6 (address = 0x1B) [Default = 00h]
        7. 7.5.4.7 CUSTOM_CTRL7 (address = 0x1C) [Default = 00h]
        8. 7.5.4.8 CUSTOM_CTRL8 (address = 0x1D) [Default = 00h]
        9. 7.5.4.9 CUSTOM_CTRL9 (address = 0x1E) [Default = 00h]
      5. 7.5.5 Auto torque Registers
        1. 7.5.5.1  ATQ_CTRL1 (address = 0x1F) [Default = 00h]
        2. 7.5.5.2  ATQ_CTRL2 (address = 0x20) [Default = 00h]
        3. 7.5.5.3  ATQ_CTRL3 (address = 0x21) [Default = 00h]
        4. 7.5.5.4  ATQ_CTRL4 (address = 0x22) [Default = 20h]
        5. 7.5.5.5  ATQ_CTRL5 (address = 0x23) [Default = 00h]
        6. 7.5.5.6  ATQ_CTRL6 (address = 0x24) [Default = 00h]
        7. 7.5.5.7  ATQ_CTRL7 (address = 0x25) [Default = 00h]
        8. 7.5.5.8  ATQ_CTRL8 (address = 0x26) [Default = 00h]
        9. 7.5.5.9  ATQ_CTRL9 (address = 0x27) [Default = 00h]
        10. 7.5.5.10 ATQ_CTRL10 (address = 0x28) [Default = 08h]
        11. 7.5.5.11 ATQ_CTRL11 (address = 0x29) [Default = 0Ah]
        12. 7.5.5.12 ATQ_CTRL12 (address = 0x2A) [Default = FFh]
        13. 7.5.5.13 ATQ_CTRL13 (address = 0x2B) [Default = 05h]
        14. 7.5.5.14 ATQ_CTRL14 (address = 0x2C) [Default = 0Fh]
        15. 7.5.5.15 ATQ_CTRL15 (address = 0x2D) [Default = 00h]
        16. 7.5.5.16 ATQ_CTRL16 (address = 0x2E) [Default = FFh]
        17. 7.5.5.17 ATQ_CTRL17 (address = 0x2F) [Default = 00h]
        18. 7.5.5.18 ATQ_CTRL18 (address = 0x30) [Default = 00h]
      6. 7.5.6 Silent Step Registers
        1. 7.5.6.1 SS_CTRL1 (address = 0x31) [Default = 00h]
        2. 7.5.6.2 SS_CTRL2 (address = 0x32) [Default = 00h]
        3. 7.5.6.3 SS_CTRL3 (address = 0x33) [Default = 00h]
        4. 7.5.6.4 SS_CTRL4 (address = 0x34) [Default = 00h]
        5. 7.5.6.5 SS_CTRL5 (address = 0x35) [Default = FFh]
  9. 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 Stepper Motor Speed
      3. 8.2.3 Application Performance Plots
      4. 8.2.4 Thermal Application
        1. 8.2.4.1 Power Dissipation
        2. 8.2.4.2 Conduction Loss
        3. 8.2.4.3 Switching Loss
        4. 8.2.4.4 Power Dissipation Due to Quiescent Current
        5. 8.2.4.5 Total Power Dissipation
        6. 8.2.4.6 Device Junction Temperature Estimation
  10. 9 Thermal Considerations
    1. 9.1 Thermal Pad
    2. 9.2 PCB Material Recommendation
  11. 10Power Supply Recommendations
    1. 10.1 Bulk Capacitance
    2. 10.2 Power Supplies
  12. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  13. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  14. 13Mechanical, Packaging, and Orderable Information

Package Options

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

8.2.4.3 Switching Loss

The power loss due to the PWM switching frequency depends on the output voltage rise/fall time (tRF), supply voltage, motor RMS current and the PWM switching frequency. The switching losses in each H-bridge during rise-time and fall-time are calculated as shown in Equation 18 and Equation 19.

Equation 18. PSW_RISE = 0.5 x VVM x IRMS x tRF x fPWM
Equation 19. PSW_FALL = 0.5 x VVM x IRMS x tRF x fPWM

The DRV8461 features two values of output rise/fall time (tRF) - 140 ns and 70 ns. The smaller rise/fall time obviously results in lesser switching loss. Assuming tRF = 140 ns and 30-kHz PWM frequencyfor this exercise, and after substituting the values of various parameters, the switching losses in each H-bridge are calculated as shown below -

Equation 20. PSW_RISE = 0.5 x 24-V x (3-A / √2) x (140 ns) x 30-kHz = 0.107-W
Equation 21. PSW_FALL = 0.5 x 24-V x (3-A / √2) x (140 ns) x 30-kHz = 0.107-W

The total switching loss for the stepper motor driver (PSW) is calculated as twice the sum of rise-time (PSW_RISE) switching loss and fall-time (PSW_FALL) switching loss as shown below -

Equation 22. PSW = 2 x (PSW_RISE + PSW_FALL) = 2 x (0.107-W + 0.107-W) = 0.428-W
Note:

The output rise/fall time (tRF) is expected to change based on the supply-voltage, temperature and device to device variation.

The switching loss is directly proportional to the PWM switching frequency. The PWM frequency in an application will depend on the supply voltage, inductance of the motor coil, back emf voltage and OFF time or the ripple current (for smart tune ripple control decay mode).