JAJSKV6D August   2020  – April 2024 DRV8714-Q1 , DRV8718-Q1

PRODMIX  

  1.   1
  2. 1 特長
  3. 2 アプリケーション
  4. 3 概要
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
    1. 5.1 VQFN (RVJ) 56-Pin Package and Pin Functions
    2. 5.2 VQFN (RHA) 40-Pin Package and Pin Functions
    3. 5.3 HTQFP (PHP) 48-Pin Package and Pin Functions
  7. 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 Timing Diagrams
    8. 6.8 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 External Components
      2. 7.3.2 Device Interface Variants
        1. 7.3.2.1 Serial Peripheral Interface (SPI)
        2. 7.3.2.2 Hardware (H/W)
      3. 7.3.3 Input PWM Control Modes
        1. 7.3.3.1 Half-Bridge Control Scheme With Input PWM Mapping
          1. 7.3.3.1.1 DRV8718-Q1 Half-Bridge Control
          2. 7.3.3.1.2 DRV8714-Q1 Half-Bridge Control
        2. 7.3.3.2 H-Bridge Control
          1. 7.3.3.2.1 DRV8714-Q1 H-Bridge Control
        3. 7.3.3.3 Split HS and LS Solenoid Control
          1. 7.3.3.3.1 DRV8714-Q1 Split HS and LS Solenoid Control
      4. 7.3.4 Smart Gate Driver
        1. 7.3.4.1 Functional Block Diagram
        2. 7.3.4.2 Slew Rate Control (IDRIVE)
        3. 7.3.4.3 Gate Drive State Machine (TDRIVE)
        4. 7.3.4.4 Propagation Delay Reduction (PDR)
          1. 7.3.4.4.1 PDR Pre-Charge/Pre-Discharge Control Loop Operation Details
            1. 7.3.4.4.1.1 PDR Pre-Charge/Pre-Discharge Setup
          2. 7.3.4.4.2 PDR Post-Charge/Post-Discharge Control Loop Operation Details
            1. 7.3.4.4.2.1 PDR Post-Charge/Post-Discharge Setup
          3. 7.3.4.4.3 Detecting Drive and Freewheel MOSFET
        5. 7.3.4.5 Automatic Duty Cycle Compensation (DCC)
        6. 7.3.4.6 Closed Loop Slew Time Control (STC)
          1. 7.3.4.6.1 STC Control Loop Setup
      5. 7.3.5 Tripler (Dual-Stage) Charge Pump
      6. 7.3.6 Wide Common-Mode Current Shunt Amplifiers
      7. 7.3.7 Pin Diagrams
        1. 7.3.7.1 Logic Level Input Pin (INx/ENx, INx/PHx, nSLEEP, nSCS, SCLK, SDI)
        2. 7.3.7.2 Logic Level Push Pull Output (SDO)
        3. 7.3.7.3 Logic Level Multi-Function Pin (DRVOFF/nFLT)
        4. 7.3.7.4 Quad-Level Input (GAIN, MODE)
        5. 7.3.7.5 Six-Level Input (IDRIVE, VDS)
      8. 7.3.8 Protection and Diagnostics
        1. 7.3.8.1  Gate Driver Disable (DRVOFF/nFLT and EN_DRV)
        2. 7.3.8.2  Low IQ Powered Off Braking (POB, BRAKE)
        3. 7.3.8.3  Fault Reset (CLR_FLT)
        4. 7.3.8.4  DVDD Logic Supply Power on Reset (DVDD_POR)
        5. 7.3.8.5  PVDD Supply Undervoltage Monitor (PVDD_UV)
        6. 7.3.8.6  PVDD Supply Overvoltage Monitor (PVDD_OV)
        7. 7.3.8.7  VCP Charge Pump Undervoltage Lockout (VCP_UV)
        8. 7.3.8.8  MOSFET VDS Overcurrent Protection (VDS_OCP)
        9. 7.3.8.9  Gate Driver Fault (VGS_GDF)
        10. 7.3.8.10 Thermal Warning (OTW)
        11. 7.3.8.11 Thermal Shutdown (OTSD)
        12. 7.3.8.12 Offline Short Circuit and Open Load Detection (OOL and OSC)
        13. 7.3.8.13 Watchdog Timer
        14. 7.3.8.14 Fault Detection and Response Summary Table
    4. 7.4 Device Functional Modes
      1. 7.4.1 Inactive or Sleep State
      2. 7.4.2 Standby State
      3. 7.4.3 Operating State
    5. 7.5 Programming
      1. 7.5.1 SPI Interface
      2. 7.5.2 SPI Format
      3. 7.5.3 SPI Interface for Multiple Slaves
        1. 7.5.3.1 SPI Interface for Multiple Slaves in Daisy Chain
  9. 8 Register Maps
    1. 8.1 DRV8718-Q1 Register Map
    2. 8.2 DRV8714-Q1 Register Map
    3. 8.3 DRV8718-Q1 Register Descriptions
      1. 8.3.1 DRV8718-Q1_STATUS Registers
      2. 8.3.2 DRV8718-Q1_CONTROL Registers
      3. 8.3.3 DRV8718-Q1_CONTROL_ADV Registers
      4. 8.3.4 DRV8718-Q1_STATUS_ADV Registers
    4. 8.4 DRV8714-Q1 Register Descriptions
      1. 8.4.1 DRV8714-Q1_STATUS Registers
      2. 8.4.2 DRV8714-Q1_CONTROL Registers
      3. 8.4.3 DRV8714-Q1_CONTROL_ADV Registers
      4. 8.4.4 DRV8714-Q1_STATUS_ADV Registers
  10. 9  Application Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Gate Driver Configuration
          1. 9.2.2.1.1 VCP Load Calculation Example
          2. 9.2.2.1.2 IDRIVE Calculation Example
          3. 9.2.2.1.3 tDRIVE Calculation Example
          4. 9.2.2.1.4 Maximum PWM Switching Frequency
        2. 9.2.2.2 Current Shunt Amplifier Configuration
        3. 9.2.2.3 Power Dissipation
      3. 9.2.3 Application Curves
    3. 9.3 Initialization
    4. 9.4 Power Supply Recommendations
      1. 9.4.1 Bulk Capacitance Sizing
    5. 9.5 Layout
      1. 9.5.1 Layout Guidelines
      2. 9.5.2 Layout Example
  11. 10Device Documentation and Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documents
    2. 10.2 ドキュメントの更新通知を受け取る方法
    3. 10.3 サポート・リソース
    4. 10.4 Trademarks
    5. 10.5 静電気放電に関する注意事項
    6. 10.6 用語集
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information
    1. 12.1 Package Option Addendum

7.3.4.3 Gate Drive State Machine (TDRIVE)

The TDRIVE component of the smart gate drive architecture is an integrated gate drive state machine that provides automatic dead time insertion, parasitic dV/dt gate coupling prevention, and MOSFET gate fault detection.

The first component of the TDRIVE state machine is an automatic dead time handshake. Dead time is the period of body diode conduction time between the switching of the external high-side and low-side MOSFET to prevent any cross conduction or shoot through. The DRV871x-Q1 uses VGS monitors to implement a break and then make dead time scheme by measuring the external MOSFET VGS voltage to determine when to properly enable the external MOSFETs. This scheme allows the gate driver to adjust the dead time for variations in the system such as temperature drift, aging, voltage fluctuations, and variation in the external MOSFET parameters. An additional fixed digital dead time (tDEAD_D) can be inserted if desired and is adjustable through the SPI registers.

The second component focuses on preventing parasitic dV/dt gate charge coupling. This is implemented by enabling a strong gate current pulldown (ISTRONG) whenever the opposite MOSFET in the half-bridge is switching. This feature helps remove parasitic charge that couples into the external MOSFET gate when the half-bridge switch node is rapidly slewing.

The third component implements a gate fault detection scheme to detect an issue with the gate voltage. This is used to detect pin-to-pin solder defects, a MOSFET gate failure, or a gate stuck high or stuck low voltage condition. This is done by using the VGS monitors to measure the gate voltage after the end of the tDRIVE time. If the gate voltage has not reached the proper threshold, the gate driver will report the corresponding fault condition. To ensure a false fault is not detected, a tDRIVE time should be selected that is longer than the time required to charge or discharge the MOSFET gate. The tDRIVE time does not impact the PWM minimum duration and will terminate early if another PWM command is received.

DRV8714-Q1 DRV8718-Q1 TDRIVE Turn On / OffFigure 7-12 TDRIVE Turn On / Off