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

7.3.6 Automatic Microstepping Mode

When the DRV8461 is operating with SPI interface, automatic microstepping mode interpolates the input step pulses to generate a current waveform corresponding to higher resolution microstep. This results in smooth sinusoidal current and noiseless operation at any step frequency.

  • If automatic microstepping is disabled, the system controller will be forced to output high frequency STEP signals to generate high resolution microstepping current waveforms.

  • With automatic microstepping enabled, smooth current waveform can be generated by low frequency STEP signals.

    • This drastically reduces controller overhead and is beneficial for applications such as 3D printer, factory automation and medical.

  • It should be ensured that the interpolated frequency does not fall in the resonant frequency band of the stepper motor.

The EN_AUTO bit should be 1b to enable the automatic microstepping mode.

GUID-20220521-SS0I-CZHS-BDHQ-1N5T7MBCWSXZ-low.svgFigure 7-7 Automatic Microstepping Interpolation
Figure 7-7 shows increment in motor angle with and without automatic microstepping. Without automatic microstepping (red plot), the motor angle increments by a large amount on every step input active edge. Automatic microstepping (green plot) results in a much smoother change in motor angle.

The DRV8461 supports interpolation to 1/32, 1/64, 1/128 or 1/256 microstepping levels, configured by the RES_AUTO bits as shown in Table 7-13. Interpolation setting can be changed on the fly.

Table 7-13 Automatic Microstepping Interpolation Level

RES_AUTO

Interpolation

00b (default)

1/256

01b

1/128

10b

1/64

11b

1/32

Table 7-14 show both coil currents and the smooth transition between half-step mode and automatic microstepping mode by writing 1b and 0b respectively to the EN_AUTO bit. Notice that the step frequency is same in both half-step and 1/256 automatic microstepping modes.

Table 7-14 Transition between half-step and automatic microstepping
GUID-20220526-SS0I-7HZK-JF4L-LRRRT503VCLW-low.pngGUID-20220526-SS0I-SZVZ-VFBG-5FHMP8JHJDHS-low.png

Transition from half-step mode to 1/256 automatic microstepping

Transition from 1/256 automatic microstepping to half-step mode

GUID-20220521-SS0I-HJHT-ZSPH-85NRCDFKNSBM-low.svgFigure 7-8 Automatic Microstepping with Changing STEP Frequency

As shown in Figure 7-8, the interpolation is done based on the time between the two previous step pulses. The previous interval time is interpolated to equal divisions, depending on the RES_AUTO bit setting.

When input step frequency reduces from previous interval (shown in segment '1'), the motor holds its position till the next STEP active edge occurs. Device will go to standstill power saving mode if the EN_STSL bit is 1b, and the next active edge does not come before tSTSL_DLY expires. Standstill power saving mode is exited on the next STEP active edge.

When step frequency increases from previous interval (shown in segment '2'), the motor angle smoothly auto-corrects when the next STEP active edge comes, and the indexer moves to a position corresponding to the STEP input. In segment '3', the motor angle is incremented at a faster rate, corresponding to the step frequency of segment '2'.

Note:

  • The frequency of the STEP input in automatic microstepping mode should be between 10 Hz and 300 kHz.

  • To realize automatic microstepping for lower than 10 Hz full step equivalent step frequency, use a higher resolution microstepping setting before enabling automatic microstepping.

    • For example, 1 Hz step frequency in full step mode corresponds to 16 Hz step frequency in 1/16 microstepping mode. So, if one wants to use automatic microstepping for a full step 1 Hz step input, MICROSTEP_MODE can be set to 0110b (1/16 microstep), and use RES_AUTO bits for desired interpolation level.