SLVSDO1C January   2017  – March 2020 DRV8886AT

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Simplified Schematic
  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 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  Current Regulation
      5. 7.3.5  Controlling RREF With an MCU DAC
        1. 7.3.5.1 Various Sources of Error
          1. 7.3.5.1.1 VRREF, ARREF, and RREF Error
          2. 7.3.5.1.2 VDAC Error
        2. 7.3.5.2 Application-Specific Error Calculations
      6. 7.3.6  Decay Modes
        1. 7.3.6.1 Mode 1: Slow Decay for Increasing Current, Mixed Decay for Decreasing Current
        2. 7.3.6.2 Mode 2: Mixed Decay for Increasing and Decreasing Current
        3. 7.3.6.3 Mode 3: Smart Tune Ripple Control
        4. 7.3.6.4 Mode 4: Smart Tune Dynamic Decay
      7. 7.3.7  Blanking Time
      8. 7.3.8  Charge Pump
      9. 7.3.9  Linear Voltage Regulators
      10. 7.3.10 Logic and Multi-Level Pin Diagrams
      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)
        4. 7.3.11.4 Thermal Shutdown (TSD)
    4. 7.4 Device Functional Modes
  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 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 Community 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

7.1 Overview

The DRV8886AT device is an integrated motor-driver solution for bipolar stepper motors. The device integrates two N-channel power MOSFET H-bridges, integrated current sense and regulation circuitry, and a microstepping indexer. The DRV8886AT device can be powered with a supply voltage from 8 to 37 V and is capable of providing an output current up to 3-A peak, 2-A full-scale, or 1.4-A root mean square (rms). The actual full-scale and rms current depends on the ambient temperature, supply voltage, and PCB thermal capability.

The DRV8886AT device uses an integrated current-sense architecture which eliminates the need for two external power sense resistors. This architecture removes the power dissipated in the sense resistors by using a current mirror approach and using the internal power MOSFETs for current sensing. The current regulation set point is adjusted with a standard low-power resistor connected to the RREF pin. This features reduces external component cost, board PCB size, and system power consumption.

A simple STEP/DIR interface allows for an external controller to manage the direction and step rate of the stepper motor. The internal indexer can execute high-accuracy microstepping without requiring the external controller to manage the winding current level. The indexer is capable of full step, half step, and 1/4, 1/8, 1/16 microstepping. In addition to a standard half stepping mode, a noncircular half stepping mode is available for increased torque output at higher motor RPM.

The current regulation is configurable between several decay modes. The decay mode can be selected as a slow-mixed, mixed decay, smart tune Ripple Control, or smart tune Dynamic Decay current regulation scheme. The slow-mixed decay mode uses slow decay on increasing steps and mixed decay on decreasing steps. The smart tune decay modes automatically adjust for optimal current regulation performance and compensate for motor variation and aging effects. smart tune Ripple Control uses a variable off-time, ripple control scheme to minimize distortion of the motor winding current. smart tune Dynamic Decay uses a fixed off-time, dynamic decay percentage scheme to minimize distortion of the motor winding current while also minimizing frequency content.

An adaptive blanking time feature automatically scales the minimum drive time with output current level. This feature helps alleviate zero-crossing distortion by limiting the drive time at low-current steps.

A torque DAC feature allows the controller to scale the output current without needing to scale the RREF reference resistor. The torque DAC is accessed using a digital input pin which allows the controller to save system power by decreasing the motor current consumption when high output torque is not required.

A low-power sleep mode is included which allows the system to save power when not actively driving the motor.