SLVSCC0D November   2013  – October 2019 DRV8850

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      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 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 Power Supervisor
      2. 7.3.2 Bridge Control
      3. 7.3.3 Current Sensing – VPROPI
      4. 7.3.4 Slew-Rate Control
      5. 7.3.5 Dead Time
      6. 7.3.6 Propagation Delay
      7. 7.3.7 Power Supplies and Input Pins
      8. 7.3.8 LDO Voltage Regulator
      9. 7.3.9 Protection Circuits
        1. 7.3.9.1 Overcurrent Protection (OCP)
        2. 7.3.9.2 Thermal Shutdown (TSD)
        3. 7.3.9.3 Undervoltage Lockout (UVLO)
        4. 7.3.9.4 Overvoltage Lockout (OVLO)
    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 Motor Voltage
        2. 8.2.2.2 Drive Current
      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
      1. 10.3.1 Power Dissipation
  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

7.3.5 Dead Time

The dead time (tDEAD) is measured as the time when OUTx is Hi-Z between turning off one of the H-bridge FETs and turning on the other. For example, the output is Hi-Z between turning off the high-side FET and turning on the low-side FET. When driving current out of the pin, the output is observed to fall to one diode drop below ground during dead time. When driving current into the pin, the output is observed to rise to one diode drop above VCC.

The DRV8850 has an analog dead time of approximately 100 ns. In addition to this analog dead time, the output is Hi-Z when the FET gate voltage is less than the threshold voltage. The total dead time depends on the SR resistor setting because a portion of the FET gate ramp includes the observable dead time.