SLLSFB6B May   2020  – May 2024 DRV8705-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Descriptions
  5.   Device Comparison Table
  6. 4 Pin Configuration
  7. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Timing Requirements
    7. 5.7 Timing Diagrams
    8. 5.8 Typical Characteristics
  8. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 External Components
      2. 6.3.2 Device Interface Variants
        1. 6.3.2.1 Serial Peripheral Interface (SPI)
        2. 6.3.2.2 Hardware (H/W)
      3. 6.3.3 Input PWM Modes
        1. 6.3.3.1 Half-Bridge Control
        2. 6.3.3.2 H-Bridge Control
        3. 6.3.3.3 Split HS and LS Solenoid Control
      4. 6.3.4 Smart Gate Driver
        1. 6.3.4.1 Functional Block Diagram
        2. 6.3.4.2 Slew Rate Control (IDRIVE)
        3. 6.3.4.3 Gate Drive State Machine (TDRIVE)
      5. 6.3.5 Doubler (Single-Stage) Charge Pump
      6. 6.3.6 Low-Side Differential Current Shunt Amplifier
      7. 6.3.7 Pin Diagrams
        1. 6.3.7.1 Logic Level Input Pin (DRVOFF, IN1/EN, IN2/PH, nHIZx, nSLEEP, nSCS, SCLK, SDI)
        2. 6.3.7.2 Logic Level Push Pull Output (SDO)
        3. 6.3.7.3 Logic Level Open Drain Output (nFAULT)
        4. 6.3.7.4 Quad-Level Input (GAIN)
        5. 6.3.7.5 Six-Level Input (IDRIVE, VDS)
      8. 6.3.8 Protection and Diagnostics
        1. 6.3.8.1  Gate Driver Disable and Enable (DRVOFF and EN_DRV)
        2. 6.3.8.2  Fault Reset (CLR_FLT)
        3. 6.3.8.3  DVDD Logic Supply Power on Reset (DVDD_POR)
        4. 6.3.8.4  PVDD Supply Undervoltage Monitor (PVDD_UV)
        5. 6.3.8.5  PVDD Supply Overvoltage Monitor (PVDD_OV)
        6. 6.3.8.6  VCP Charge Pump Undervoltage Lockout (VCP_UV)
        7. 6.3.8.7  MOSFET VDS Overcurrent Protection (VDS_OCP)
        8. 6.3.8.8  Gate Driver Fault (VGS_GDF)
        9. 6.3.8.9  Thermal Warning (OTW)
        10. 6.3.8.10 Thermal Shutdown (OTSD)
        11. 6.3.8.11 Offline Short Circuit and Open Load Detection (OOL and OSC)
        12. 6.3.8.12 Fault Detection and Response Summary Table
    4. 6.4 Device Function Modes
      1. 6.4.1 Inactive or Sleep State
      2. 6.4.2 Standby State
      3. 6.4.3 Operating State
    5. 6.5 Programming
      1. 6.5.1 SPI Interface
      2. 6.5.2 SPI Format
      3. 6.5.3 SPI Interface for Multiple Slaves
        1. 6.5.3.1 SPI Interface for Multiple Slaves in Daisy Chain
  9. 7 Register Maps
    1. 7.1 STATUS Registers
    2. 7.2 CONTROL Registers
  10. 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 Gate Driver Configuration
          1. 8.2.2.1.1 VCP Load Calculation Example
          2. 8.2.2.1.2 IDRIVE Calculation Example
        2. 8.2.2.2 Current Shunt Amplifier Configuration
        3. 8.2.2.3 Power Dissipation
  11. 9 Power Supply Recommendations
    1. 9.1 Bulk Capacitance
  12. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  13. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
      2. 11.1.2 Receiving Notification of Documentation Updates
    2. 11.2 Support Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  14. 12Revision History
  15. 13Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • RHB|32
Thermal pad, mechanical data (Package|Pins)
Orderable Information
8.2.2.1.2 IDRIVE Calculation Example

The gate drive current strength, IDRIVE, is selected based on the gate-to-drain charge of the external MOSFETs and the target rise and fall times at the switch-node. If IDRIVE is selected to be too low for a given MOSFET, then the MOSFET may not turn on or off completely within the configured tDRIVE time and a gate fault may be asserted. Additionally, slow rise and fall times will lead to higher switching power losses in the external power MOSFETs. It is recommended to verify these values in system with the required external MOSFETs and load to determine the optimal settings.

The IDRIVEP and IDRIVEN for both the high-side and low-side external MOSFETs are independently adjustable on SPI device variants. On hardware interface device variants, both source and sink settings are selected simultaneously on the IDRIVE pin.

For MOSFETs with a known gate-to-drain charge (QGD), desired rise time (trise), and a desired fall time (tfall), use Equation 3 and Equation 4 to calculate the approximate values of IDRIVEP and IDRIVEN (respectively).

Equation 3. IDRIVEP = QGD / trise
Equation 4. IDRIVEN = QGD / tfall

Using the input design parameters as an example, we can calculate the approximate values for IDRIVEP and IDRIVEN.

Equation 5. IDRIVEP_HI = 5 nC / 750 ns = 6.67 mA
Equation 6. IDRIVEP_LO = 5 nC / 1000 ns = 5 mA

Based on these calculations a value of 6 mA was chosen for IDRIVEP.

Equation 7. IDRIVEN_HI = 5 nC / 250 ns = 20 mA
Equation 8. IDRIVEN_LO = 5 nC / 500 ns = 10 mA

Based on these calculations a value of 16 mA was chosen for IDRIVEN.