SLOSE37B June   2020  – May 2022 DRV8436

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1. 5.1 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 Indexer Timing Requirements
    7. 6.7 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 Mixed Decay for Increasing and Decreasing Current
        4. 7.3.6.4 Smart tune Dynamic Decay
        5. 7.3.6.5 Smart tune Ripple Control
        6. 7.3.6.6 PWM OFF Time
        7. 7.3.6.7 Blanking time
      7. 7.3.7  Charge Pump
      8. 7.3.8  Linear Voltage Regulators
      9. 7.3.9  Logic Level, tri-level and quad-level Pin Diagrams
        1. 7.3.9.1 nFAULT Pin
      10. 7.3.10 Protection Circuits
        1. 7.3.10.1 VM Undervoltage Lockout (UVLO)
        2. 7.3.10.2 VCP Undervoltage Lockout (CPUV)
        3. 7.3.10.3 Overcurrent Protection (OCP)
          1. 7.3.10.3.1 Latched Shutdown
          2. 7.3.10.3.2 Automatic Retry
        4. 7.3.10.4 Thermal Shutdown (OTSD)
        5. 7.3.10.5 Fault Condition Summary
    4. 7.4 Device Functional Modes
      1. 7.4.1 Sleep Mode (nSLEEP = 0)
      2. 7.4.2 Disable Mode (nSLEEP = 1, ENABLE = 0)
      3. 7.4.3 Operating Mode (nSLEEP = 1, ENABLE = Hi-Z/1)
      4. 7.4.4 nSLEEP Reset Pulse
      5. 7.4.5 Functional Modes Summary
  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
  9. 9 Thermal Application
    1. 9.1 Power Dissipation
      1. 9.1.1 Conduction Loss
      2. 9.1.2 Switching Loss
      3. 9.1.3 Power Dissipation Due to Quiescent Current
      4. 9.1.4 Total Power Dissipation
    2. 9.2 Device Junction Temperature Estimation
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Examples
  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 Community Resources
    4. 11.4 Trademarks
  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 1 to calculate ƒstep for a desired motor speed (v), microstepping level (nm), and motor full step angle (θstep)

Equation 1. GUID-FF5F0738-FBD3-4167-A8F6-484E813A45E4-low.gif

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

For the DRV8436, the microstepping level is set by the M0 and M1 pins 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
M0M1STEP MODE
00Full step (2-phase excitation) with 100% current
0330 kΩ to GNDFull step (2-phase excitation) with 71% current
10Non-circular 1/2 step
Hi-Z01/2 step
011/4 step
111/8 step
Hi-Z11/16 step
0Hi-Z1/32 step
Hi-Z330 kΩ to GND1/64 step
Hi-ZHi-Z1/128 step
1Hi-Z1/256 step

For example, the motor is 1.8°/step for a target of 120 rpm at 1/8 microstep mode.

Equation 2. GUID-A11802EA-EF3F-402D-B617-4B8BB00CB127-low.gif