SLVSEE9D April   2020  – April 2021 DRV8889-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin 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 SPI Timing Requirements
    7. 6.7 Indexer Timing Requirements
    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  Stepper Motor Driver Current Ratings
        1. 7.3.1.1 Peak Current Rating
        2. 7.3.1.2 rms Current Rating
        3. 7.3.1.3 Full-Scale Current Rating
      2. 7.3.2  PWM Motor Drivers
      3. 7.3.3  Microstepping Indexer
      4. 7.3.4  Controlling VREF with an MCU DAC
      5. 7.3.5  Current Regulation
      6. 7.3.6  Decay Modes
        1. 7.3.6.1 Slow Decay for Increasing and Decreasing Current
        2. 7.3.6.2 Slow Decay for Increasing Current, Mixed Decay for Decreasing Current
        3. 7.3.6.3 Mode 4: Slow Decay for Increasing Current, Fast Decay for Decreasing current
        4. 7.3.6.4 Mixed Decay for Increasing and Decreasing Current
        5. 7.3.6.5 Smart tune Dynamic Decay
        6. 7.3.6.6 Smart tune Ripple Control
      7. 7.3.7  Blanking Time
      8. 7.3.8  Charge Pump
      9. 7.3.9  Linear Voltage Regulators
      10. 7.3.10 Logic Level Pin Diagrams
        1. 7.3.10.1 nFAULT Pin
      11. 7.3.11 Protection Circuits
        1. 7.3.11.1 VM Undervoltage Lockout (UVLO)
        2. 7.3.11.2 VCP Undervoltage Lockout (CPUV)
        3. 7.3.11.3 Overcurrent Protection (OCP)
          1. 7.3.11.3.1 Latched Shutdown (OCP_MODE = 0b)
          2. 7.3.11.3.2 Automatic Retry (OCP_MODE = 1b)
        4. 7.3.11.4 Open-Load Detection (OL)
        5. 7.3.11.5 Stall Detection
        6. 7.3.11.6 Thermal Shutdown (OTSD)
          1. 7.3.11.6.1 Latched Shutdown (OTSD_MODE = 0b)
          2. 7.3.11.6.2 Automatic Recovery (OTSD_MODE = 1b)
        7. 7.3.11.7 Overtemperature Warning (OTW)
        8. 7.3.11.8 Undertemperature Warning (UTW)
        9.       53
    4. 7.4 Device Functional Modes
      1. 7.4.1 Sleep Mode (nSLEEP = 0)
      2. 7.4.2 Disable Mode (nSLEEP = 1, DRVOFF = 1)
      3. 7.4.3 Operating Mode (nSLEEP = 1, DRVOFF = 0)
      4. 7.4.4 nSLEEP Reset Pulse
      5.      59
    5. 7.5 Programming
      1. 7.5.1 Serial Peripheral Interface (SPI) Communication
        1. 7.5.1.1 SPI Format
        2. 7.5.1.2 SPI for a Single Slave Device
        3. 7.5.1.3 SPI for Multiple Slave Devices in Parallel Configuration
        4. 7.5.1.4 SPI for Multiple Slave Devices in Daisy Chain Configuration
    6. 7.6 Register Maps
  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 Stepper Motor Speed
        2. 8.2.2.2 Current Regulation
        3. 8.2.2.3 Decay Modes
      3. 8.2.3 Application Curves
      4. 8.2.4 Thermal Application
        1. 8.2.4.1 Power Dissipation
          1. 8.2.4.1.1 Conduction Loss
          2. 8.2.4.1.2 Switching Loss
          3. 8.2.4.1.3 Power Dissipation Due to Quiescent Current
          4. 8.2.4.1.4 Total Power Dissipation
        2. 8.2.4.2 PCB Types
        3. 8.2.4.3 Thermal Parameters for HTSSOP Package
        4. 8.2.4.4 Thermal Parameters for VQFN Package
        5. 8.2.4.5 Device Junction Temperature Estimation
  9. 9 Power Supply Recommendations
    1. 9.1 Bulk Capacitance
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

8.2.2.1 Stepper Motor Speed

The first step in configuring the device requires the desired motor speed and microstepping level. If the target application requires a constant speed, then a square wave with frequency ƒstep must be applied to the STEP pin. If the target motor speed is too high, the motor does not spin. Make sure that the motor can support the target speed. Use Equation 2 to calculate ƒstep for a desired motor speed (v), microstepping level (nm), and motor full step angle (θstep)

Equation 2. GUID-021E05D5-A80A-4753-B4BD-ADAFB242B241-low.gif

The value of θstep can be found in the stepper motor data sheet, or written on the motor.

For example, the motor in this adaptive headlight application is required to rotate at 15°/step for a target of 300 rpm at 1/8 microstep mode. Using Equation 2, ƒstep can be calculated as 960 Hz.

The microstepping level is set by the MICROSTEP_MODE bits in the SPI register and can be any of the settings listed in Table 8-2. Higher microstepping results in a smoother motor motion and less audible noise, but increases switching losses and requires a higher ƒstep to achieve the same motor speed.

Table 8-2 Microstepping Indexer Settings
MICROSTEP_MODESTEP MODE
0000bFull step (2-phase excitation) with 100% current
0001bFull step (2-phase excitation) with 71% current
0010bNon-circular 1/2 step
0011b1/2 step
0100b1/4 step
0101b1/8 step
0110b1/16 step
0111b1/32 step
1000b1/64 step
1001b1/128 step
1010b1/256 step