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

7.3.8 LDO Voltage Regulator

An LDO regulator is integrated into the DRV8850 device. The LDO regulator is typically used to provide the supply voltage for a low-power microcontroller. For proper operation, bypass the LDOOUT pin to GND using a ceramic capacitor. The recommended value for this component is 2.2 μF.

Two external resistors are used to set the LDO voltage (VLDO) by creating a voltage divider between LDOOUT and LDOFB. The LDO output voltage can be given by:

Equation 2. DRV8850 eq_page11_SLVSCC0.gif

where

  • R1 is located between LDOOUT and LDOFB
  • R2 is between LDOFB and GND
DRV8850 sch_LDO_regulator_SLVSCC0.gifFigure 18. LDO Regulator Schematic

The output voltage is adjustable from 1.6 V to VCC – VLDO using external resistors. The LDOEN pin is used to enable or disable the LDO regulator; when disabled, the output is turned off and the LDO regulator enters a very-low-power state.

When the LDO current load exceeds ICL, the LDO regulator behaves like a constant current source. The LDO output voltage drops significantly with currents greater than ICL.