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

7.3.3 Current Sensing – VPROPI

The VPROPI pin outputs an analog current that is proportional to the current flowing in the H-bridge. The output current is typically 1 / 2000 of the current in both high side FETs. VPROPI is derived from the current through either of the high side FETs. Because of this, VPROPI does not represent the H-bridge current when operating in a fast-decay mode or low-side slow-decay mode. VPROPI represents the H-bridge current under forward drive, reverse drive, and high-side slow decay. VPROPI output is delayed by roughly 2 µs after the high side FET is switched on and it has reached approximately VCC (including the deglitch on the HSon). Select the external resistor so that the voltage on VPROPI is less than (VCC – 1 V), so the resistor must be sized less than:

Equation 1. DRV8850 eq_page8_SLVSCC0.gif

where IOUT is the maximum drive current to be monitored

The range of current that can be monitored is 500 mA to 5 A, assuming the external resistor meets Equation 1.

DRV8850 sch_forward_reverse_SLVSCC0.gifFigure 14. Forward and Reverse Operation

When using an independent half-bridge as a high-side driver, VPROPI does not output a current measurement during slow decay. During typical operation, VPROPI represents the total current flowing to loads connected to OUT1 and OUT2.

VPROPI is nonfunctional when implemented as a low-side driver.

DRV8850 sch_high_low_driver_SLVSCC0.gifFigure 15. High-Side and Low-Side Drivers