SLVSNG2 August   2026 DRV8378-Q1

ADVANCE INFORMATION  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings AUTO
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 SPI Timing Requirements
    7. 6.7 SPI Mode Timings
  8. 7 Detailed Description
    1. 7.1  Overview
    2. 7.2  Functional Block Diagram
    3. 7.3  Feature Description
      1. 7.3.1 Output Stage
      2. 7.3.2 Device Interface Modes
        1. 7.3.2.1 Serial Peripheral Interface (SPI)
        2. 7.3.2.2 Hardware Interface
      3. 7.3.3 Control Modes
        1. 7.3.3.1 3x PWM Mode (PWM_MODE = 10b or 11b or MODE_SR Pin is Connected to GVDD with RMODE or to GVDD)
        2. 7.3.3.2 6x PWM Mode (PWM_MODE = 00b or 01b or MODE_SR Pin Tied to AGND or in Hi-Z)
        3. 7.3.3.3 DRV8378G Control mode with External GVDD
      4. 7.3.4 GVDD Linear Voltage Regulator
      5. 7.3.5 Charge Pump
    4. 7.4  Slew Rate Control
    5. 7.5  Cross Conduction (Dead Time)
    6. 7.6  Propagation Delay
    7. 7.7  Pin Diagrams
      1. 7.7.1 Logic Level Input Pin (Internal Pulldown)
      2. 7.7.2 Logic Level Input Pin (Internal Pullup)
      3. 7.7.3 Open Drain Pin
      4. 7.7.4 Push Pull Pin
    8. 7.8  Current Sense Amplifiers
      1. 7.8.1 Current Sense Amplifier Operation (29-pin variant)
    9. 7.9  Active Demagnetization
      1. 7.9.1 Automatic Synchronous Rectification Mode (ASR Mode)
        1. 7.9.1.1 Automatic Synchronous Rectification in Commutation
        2. 7.9.1.2 Automatic Synchronous Rectification in PWM Mode
      2. 7.9.2 Automatic Asynchronous Rectification Mode (AAR Mode)
    10. 7.10 Cycle-by-Cycle Current Limit
      1. 7.10.1 Cycle by Cycle Current Limit with 100% Duty Cycle Input
    11. 7.11 Protections
      1. 7.11.1 Overcurrent Protection (OCP)
        1. 7.11.1.1 OCP Latched Shutdown (OCP_MODE = 00b)
        2. 7.11.1.2 OCP Automatic Retry (OCP_MODE = 01b)
        3. 7.11.1.3 OCP Disabled (OCP_MODE = 11b)
        4. 7.11.1.4 OCP Report Only (OCP_MODE = 10b)
      2. 7.11.2 VM Supply Undervoltage Lockout (RESET)
      3. 7.11.3 GVDD Undervoltage Lockout (GVDD_UV)
      4. 7.11.4 VCP Charge Pump Undervoltage Lockout (CPUV)
      5. 7.11.5 Over Voltage Protections (OV)
      6. 7.11.6 Thermal Warning (OTW)
      7. 7.11.7 Thermal Shutdown (OTS)
    12. 7.12 Device Functional Modes
      1. 7.12.1 Functional Modes
        1. 7.12.1.1 Sleep Mode
        2. 7.12.1.2 Operating Mode
        3. 7.12.1.3 Fault Reset (CLR_FLT or nSLEEP Reset Pulse)
      2. 7.12.2 DRVOFF functionality
    13. 7.13 SPI Communication
      1. 7.13.1 Programming
        1. 7.13.1.1 SPI Format
  9. 8 Register Map
    1. 8.1 CONTROL Registers
    2. 8.2 STATUS Registers
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Power Supply Recommendations
      1. 9.2.1 Bulk Capacitance
    3. 9.3 Layout
      1. 9.3.1 Layout Guidelines
      2. 9.3.2 Layout Example
      3. 9.3.3 Thermal Considerations
        1. 9.3.3.1 Power Dissipation
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information
    1.     PACKAGE OPTION ADDENDUM
    2. 11.1 Tape and Reel Information

9.2.1 Bulk Capacitance

Having an appropriate local bulk capacitance is an important factor in motor drive system design. Having more bulk capacitance is generally more beneficial, while the disadvantages are increased cost and physical size.

The amount of local capacitance needed depends on a variety of factors, including:

  • The highest current required by the motor system
  • The capacitance and current capability of the power supply
  • The amount of parasitic inductance between the power supply and motor system
  • The acceptable voltage ripple
  • The type of motor used (brushed dc, brushless DC, stepper)
  • The motor braking method

The inductance between the power supply and the motor drive system limits the rate current can change from the power supply. If the local bulk capacitance is too small, the system responds to excessive current demands or dumps from the motor with a change in voltage. When adequate bulk capacitance is used, the motor voltage remains stable and high current can be quickly supplied.

The data sheet generally provides a recommended value, but system-level testing is required to determine the appropriate sized bulk capacitor.

DRV8378-Q1 Example Setup of Motor Drive System With External Power SupplyFigure 9-4 Example Setup of Motor Drive System With External Power Supply

The voltage rating for bulk capacitors must be higher than the operating voltage, to provide margin for cases when the motor transfers energy to the supply.