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

7.3.13.3 PD Control Loop

Table 7-26 describes the major parameters associated with the PD control loop -

Table 7-26 Parameters for PD control loop

Parameter

Description

KP[7:0], KD[3:0]

Proportional and differential gain parameters for the PD control loop.

ATQ_AVG[2:0]

The ATQ_CNT parameter is a moving average of ATQ_AVG number of half-cycles. Therefore, a high value for ATQ_AVG slows down the loop response time to a sudden peak load demand, but ensures smooth jerk-free transition to higher torque output. A low value causes the loop to respond immediately to a sudden load demand.

  • 010b - 2 cycle average

  • 100b - 4 cycle average

  • 111b - 8 cycle average

  • Other values : no averaging

ATQ_FRZ[2:0]

Delay in electrical half-cycles after which current is changed in response to the PD loop. A small value increases the current quickly to meet peak load demand. This parameter has a range of 1 to 7.

001b - Fastest response time, but the loop can become unstable

111b - Slowest response, but the loop will be stable

ATQ_D_THR[7:0]

If error change is less then ATQ_D_THR, then KD does not contribute to correction. KD contributes only when error change is greater than ATQ_D_THR.

For example: if ATQ_D_THR = 10,

If error change is 9, u(t) = KP * e(t)

If error change is 12, then u(t) = KP * e(t) + KD * de(t)/dt

ATQ_ERROR_TRUNCATE[3:0]

Number of LSB bits truncated from error before used in PD loop equations. A high value reduces any oscillation in the current waveform.

The PD control algorithm is expressed as -

Equation 14. u(t) = KP * e(t) + KD * de(t)/dt

where,

KP and KD = PD loop constants

u(t) = output of controller

e(t) = error signal

  • In general, increasing the KP will increase the speed of the control system response.

  • However, if KP is too large, the current waveform will start to oscillate.

  • If KP is increased further, the oscillations will become larger. The system will become unstable and may even oscillate out of control.

  • Increasing the value of KD will cause the control system to react more strongly to changes in the error term and will increase the speed of the overall control system response.

  • It is recommended to use small value of KD, because the derivative response is highly sensitive to noise.

  • When non-zero values of KD is selected, to improve noise immunity of the system, a high value of ATQ_D_THR should be used.

Guidelines to tune the PD loop parameters are as follows -

  • Set KP = 1, KD = 0, all other PD loop parameters should be at their default values

  • Apply load profile specific to the application

  • If the motor stalls, increase KP, KD and decrease ATQ_D_THR till the motor stops stalling

  • Once the motor does not stall any more, observe the current waveform at constant load torques

  • If the current waveform has oscillations, increase ATQ_FRZ, ATQ_AVG and ATQ_ERROR_TRUNCATE

  • Very high values of ATQ_FRZ, ATQ_AVG and ATQ_ERROR_TRUNCATE can deteriorate load transient response, so it is recommended to check load transient response once more to ensure the PD control loop is stable.

Figure 7-29 is the flowchart for selecting PD control loop parameters.

GUID-20220606-SS0I-PQMZ-HK2W-LWXQBJL1QPLH-low.svgFigure 7-29 Selecting PD control loop parameters