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

9.2.2.3 Power Dissipation

In high ambient operating environments, it may be important to estimate the internal self heating of the driver. To determine the temperature of the device, first the internal power dissipation must be calculate. After this an estimate can be made with the device package thermal properties.

The internal power dissipation has four primary components.

  • High-Side Driver Power Dissipation (PHS)
  • Low-Side Driver Power Dissipation (PLS)
  • PVDD Battery Supply Power Dissipation (PPVDD)
  • DVDD/AREF Logic/Reference Supply Power Dissipation (PVCC)

The values for PHS and PLS can be approximated by referencing the earlier equation for charge pump load current as shown below. In a typical switch scenario, 4 high-side and 4 low-side MOSFET are switching.

Equation 19. IHS/LS (A) = QG (C) x fPWM (Hz) x # of switching FETs

Using the input design parameters as an example, we can calculate the current load from the high-side and low-side drivers.

Equation 20. IHS = 30 nC x 20 kHz x 4 = 2.4 mA
Equation 21. ILS = 30 nC x 20 kHz x 4 = 2.4 mA

From this, the power dissipation can be calculated from the equations below for the driver power dissipation. The high-side and low-side includes a doubling factor to account for the losses in the charge pump supplying the drivers.

Equation 22. PHS (W) = IHS (A) x VPVDD x 2
Equation 23. PLS (W) = ILS (A) x VPVDD x 2

Using the input design parameters as an example, we can calculate the power dissipation from the high-side and low-side drivers.

Equation 24. PHS (W) = 0.0576 W = 2.4 mA x 12 V x 2
Equation 25. PLS (W) = 0.0576 W = 2.4 mA x 12 V x 2

The values for PPVDD and PVCC can be approximated by referencing Equation 26 and Equation 27:

Equation 26. PPVDD (W) = IPVDD (A) x VPVDD
Equation 27. PVCC (W) = (IDVDD (A) x VDVDD) + (IAREF (A) x VAREF)

Using the input design parameters as an example, we can calculate the power dissipation for the power supplies.

Equation 28. PPVDD (W) = 0.162 W = 13.5 mA x 12 V
Equation 29. PVCC (W) = 0.033 W = (8 mA x 3.3 V) + (2 mA x 3.3 V)

Finally, use Equation 30 to estimate device junction temperature.

Equation 30. TJUNCTION (°C) = TAMBIENT (°C) + (RθJA (°C/W) x PTOT(W))

Using the previously calculated power dissipation values and the device thermal parameter from the Thermal Information table can estimate the device internal temperature:

Equation 31. TJUNCTION (°C) = 112.9 °C = 105 °C + (25.6 °C/W x 0.3102 W)