SLVSFN2B September   2021  – February 2022 DRV8311

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 SPI Timing Requirements
    7. 7.7 SPI Secondary Device Mode Timings
    8. 7.8 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Output Stage
      2. 8.3.2  Control Modes
        1. 8.3.2.1 6x PWM Mode (DRV8311S and DRV8311H variants only)
        2. 8.3.2.2 3x PWM Mode (DRV8311S and DRV8311H variants only)
        3. 8.3.2.3 PWM Generation Mode (DRV8311S and DRV8311P Variants)
      3. 8.3.3  Device Interface Modes
        1. 8.3.3.1 Serial Peripheral Interface (SPI)
        2. 8.3.3.2 Hardware Interface
      4. 8.3.4  AVDD Linear Voltage Regulator
      5. 8.3.5  Charge Pump
      6. 8.3.6  Slew Rate Control
      7. 8.3.7  Cross Conduction (Dead Time)
      8. 8.3.8  Propagation Delay
      9. 8.3.9  Pin Diagrams
        1. 8.3.9.1 Logic Level Input Pin (Internal Pulldown)
        2. 8.3.9.2 Logic Level Input Pin (Internal Pullup)
        3. 8.3.9.3 Open Drain Pin
        4. 8.3.9.4 Push Pull Pin
        5. 8.3.9.5 Four Level Input Pin
      10. 8.3.10 Current Sense Amplifiers
        1. 8.3.10.1 Current Sense Amplifier Operation
        2. 8.3.10.2 Current Sense Amplifier Offset Correction
      11. 8.3.11 Protections
        1. 8.3.11.1 VM Supply Undervoltage Lockout (NPOR)
        2. 8.3.11.2 Under Voltage Protections (UVP)
        3. 8.3.11.3 Overcurrent Protection (OCP)
          1. 8.3.11.3.1 OCP Latched Shutdown (OCP_MODE = 010b)
          2. 8.3.11.3.2 OCP Automatic Retry (OCP_MODE = 000b or 001b)
          3. 8.3.11.3.3 OCP Report Only (OCP_MODE = 011b)
          4. 8.3.11.3.4 OCP Disabled (OCP_MODE = 111b)
        4. 8.3.11.4 Thermal Protections
          1. 8.3.11.4.1 Thermal Warning (OTW)
          2. 8.3.11.4.2 Thermal Shutdown (OTSD)
    4. 8.4 Device Functional Modes
      1. 8.4.1 Functional Modes
        1. 8.4.1.1 Sleep Mode
        2. 8.4.1.2 Operating Mode
        3. 8.4.1.3 Fault Reset (CLR_FLT or nSLEEP Reset Pulse)
    5. 8.5 SPI Communication
      1. 8.5.1 Programming
        1. 8.5.1.1 SPI and tSPI Format
  9. 9 DRV8311 Registers
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Applications
      1. 10.2.1 Three-Phase Brushless-DC Motor Control
        1. 10.2.1.1 Detailed Design Procedure
          1. 10.2.1.1.1 Motor Voltage
        2. 10.2.1.2 Driver Propagation Delay and Dead Time
        3. 10.2.1.3 Delay Compensation
        4. 10.2.1.4 Current Sensing and Output Filtering
        5. 10.2.1.5 Application Curves
    3. 10.3 Three Phase Brushless-DC tSPI Motor Control
      1. 10.3.1 Detailed Design Procedure
    4. 10.4 Alternate Applications
  11. 11Power Supply Recommendations
    1. 11.1 Bulk Capacitance
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
    3. 12.3 Thermal Considerations
      1. 12.3.1 Power Dissipation and Junction Temperature Estimation
  13. 13Device and Documentation Support
    1. 13.1 Support Resources
    2. 13.2 Trademarks
    3. 13.3 Electrostatic Discharge Caution
    4. 13.4 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

10.2.1.2 Driver Propagation Delay and Dead Time

The propagation delay is defined as the time taken for changing input logic edges INHx and INLx (whichever changes first if MCU dead time is added) to change the half-bridge output voltage (OUTx). Driver propagation delay (tPD) and dead time (tdead) is specified with a typical and maximum value, but not with a minimum value. This is because the propagation delay can be smaller than typical depending on the direction of current at the OUTx pin during synchronous switching. Driver propagation delay and dead time can be more than typical values due to slower internal turn-ons of the high-side or low-side internal MOSFETs to avoid internal dV/dt coupling.

For more information and examples of how propagation delay and dead time differs for input PWM and output configurations, refer Delay and Dead Time in Integrated MOSFET Drivers.

The dead time from the microcontroller’s PWM outputs can be used as an extra precaution in addition to the DRV8311 internal shoot-through protection. The DRV8311 uses an internal logic prioritizes the MCU dead time or driver dead time based on their durations.

If the MCU dead time is less than the DRV8311 driver dead time, the driver will compensate and make the true output dead time with the value specified by the DRV8311. If the MCU inserted dead time is larger than the driver dead time, then the DRV8311 will adjust timing as per the MCU dead time.

A summary of the DRV8311 delay times with respect to synchronous inputs INHx and INLx, OUTx current direction, and MCU dead time are listed in Table 10-2.

Table 10-2 Summary of Delay Times in DRV8311 Depending on Logic Inputs and Output Current Direction
OUTx Current Direction INHx INLx Propagation Delay (tPD) Dead Time (tdead) Inserted MCU Dead Time (tdead(MCU))
tdead(MCU) < tdead tdead(MCU) > tdead
Out of OUTx Rising Falling Typical Typical Output dead time = tdead Output dead time = tdead(MCU)
Falling Rising Smaller than typical Smaller than typical Output dead time < tdead Output dead time < tdead(MCU)
Into OUTx Rising Falling Smaller than typical Smaller than typical Output dead time < tdead Output dead time < tdead(MCU)
Falling Rising Typical Typical Output dead time = tdead Output dead time = tdead(MCU)