SLVSCY8B August   2015  – July 2016 DRV8870

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
      2.      H-Bridge States
  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 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 Bridge Control
      2. 7.3.2 Sleep Mode
      3. 7.3.3 Current Regulation
      4. 7.3.4 Dead Time
      5. 7.3.5 Protection Circuits
        1. 7.3.5.1 VM Undervoltage Lockout (UVLO)
        2. 7.3.5.2 Overcurrent Protection (OCP)
        3. 7.3.5.3 Thermal Shutdown (TSD)
    4. 7.4 Device Functional Modes
      1. 7.4.1 PWM With Current Regulation
      2. 7.4.2 PWM Without Current Regulation
      3. 7.4.3 Static Inputs With Current Regulation
      4. 7.4.4 VM Control
  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 Motor Voltage
        2. 8.2.2.2 Drive Current
        3. 8.2.2.3 Sense Resistor
      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
    3. 10.3 Thermal Considerations
    4. 10.4 Power Dissipation
      1. 10.4.1 Heatsinking
  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

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • DDA|8
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.3.1 Bridge Control

The DRV8870 output consists of four N-channel MOSFETs that are designed to drive high current. These outputs are controlled by the two logic inputs IN1 and IN2 as listed in Table 1.

Table 1. H-Bridge Control

IN1 IN2 OUT1 OUT2 DESCRIPTION
0 0 High-Z High-Z Coast; H-bridge disabled to High-Z (sleep entered after 1 ms)
0 1 L H Reverse (Current OUT2 → OUT1)
1 0 H L Forward (Current OUT1 → OUT2)
1 1 L L Brake; low-side slow decay

The inputs can be set to static voltages for 100% duty cycle drive, or they can be pulse-width modulated (PWM) for variable motor speed. When using PWM, switching between driving and braking typically works best. For example, to drive a motor forward with 50% of the maximum RPM, IN1 = 1 and IN2 = 0 during the driving period, and IN1 = 1 and IN2 = 1 during the other period. Alternatively, the coast mode (IN1 = 0, IN2 = 0) for fast current decay is also available. The input pins can be powered before VM is applied.

DRV8870 bridge_control_lvscy8.gifFigure 4. H-Bridge Current Paths