SLVSD12D May   2015  – July 2019 DRV8305-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 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 SPI Timing Requirements (Slave Mode Only)
    7. 6.7 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Integrated Three-Phase Gate Driver
      2. 7.3.2 INHx/INLx: Gate Driver Input Modes
      3. 7.3.3 VCPH Charge Pump: High-Side Gate Supply
      4. 7.3.4 VCP_LSD LDO: Low-Side Gate Supply
      5. 7.3.5 GHx/GLx: Half-Bridge Gate Drivers
        1. 7.3.5.1 Smart Gate Drive Architecture: IDRIVE
        2. 7.3.5.2 Smart Gate Drive Architecture: TDRIVE
        3. 7.3.5.3 CSAs: Current Shunt Amplifiers
      6. 7.3.6 DVDD and AVDD: Internal Voltage Regulators
      7. 7.3.7 VREG: Voltage Regulator Output
      8. 7.3.8 Protection Features
        1. 7.3.8.1 Fault and Warning Classification
        2. 7.3.8.2 MOSFET Shoot-Through Protection (TDRIVE)
        3. 7.3.8.3 MOSFET Overcurrent Protection (VDS_OCP)
          1. 7.3.8.3.1 MOSFET dV/dt Turn On Protection (TDRIVE)
          2. 7.3.8.3.2 MOSFET Gate Drive Protection (GDF)
        4. 7.3.8.4 Low-Side Source Monitors (SNS_OCP)
        5. 7.3.8.5 Fault and Warning Operating Modes
      9. 7.3.9 Undervoltage Warning (UVFL), Undervoltage Lockout (UVLO), and Overvoltage (OV) Protection
        1. 7.3.9.1 Overtemperature Warning (OTW) and Shutdown (OTSD) Protection
        2. 7.3.9.2 Reverse Supply Protection
        3. 7.3.9.3 MCU Watchdog
        4. 7.3.9.4 VREG Undervoltage (VREG_UV)
        5. 7.3.9.5 Latched Fault Reset Methods
    4. 7.4 Device Functional Modes
      1. 7.4.1 Power Up Sequence
      2. 7.4.2 Standby State
      3. 7.4.3 Operating State
      4. 7.4.4 Sleep State
      5. 7.4.5 Limp Home or Fail Code Operation
    5. 7.5 Programming
      1. 7.5.1 SPI Communication
        1. 7.5.1.1 SPI
        2. 7.5.1.2 SPI Format
    6. 7.6 Register Maps
      1. 7.6.1 Status Registers
        1. 7.6.1.1 Warning and Watchdog Reset (Address = 0x1)
          1. Table 10. Warning and Watchdog Reset Register Description
        2. 7.6.1.2 OV/VDS Faults (Address = 0x2)
          1. Table 11. OV/VDS Faults Register Description
        3. 7.6.1.3 IC Faults (Address = 0x3)
          1. Table 12. IC Faults Register Description
        4. 7.6.1.4 VGS Faults (Address = 0x4)
          1. Table 13. Gate Driver VGS Faults Register Description
      2. 7.6.2 Control Registers
        1. 7.6.2.1 HS Gate Drive Control (Address = 0x5)
          1. Table 14. HS Gate Driver Control Register Description
        2. 7.6.2.2 LS Gate Drive Control (Address = 0x6)
          1. Table 15. LS Gate Driver Control Register Description
        3. 7.6.2.3 Gate Drive Control (Address = 0x7)
          1. Table 16. Gate Drive Control Register Description
        4. 7.6.2.4 IC Operation (Address = 0x9)
          1. Table 17. IC Operation Register Description
        5. 7.6.2.5 Shunt Amplifier Control (Address = 0xA)
          1. Table 18. Shunt Amplifier Control Register Description
        6. 7.6.2.6 Voltage Regulator Control (Address = 0xB)
          1. Table 19. Voltage Regulator Control Register Description
        7. 7.6.2.7 VDS Sense Control (Address = 0xC)
          1. Table 20. VDS Sense Control Register Description
  8. 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 Drive Average Current
        2. 8.2.2.2 MOSFET Slew Rates
        3. 8.2.2.3 Overcurrent Protection
        4. 8.2.2.4 Current Sense Amplifiers
      3. 8.2.3 VREG Reference Voltage Input (DRV8305N)
      4. 8.2.4 Application Curves
  9. 9 Power Supply Recommendations
    1. 9.1 Power Supply Consideration in Generator Mode
    2. 9.2 Bulk Capacitance
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.5.2 Smart Gate Drive Architecture: TDRIVE

The DRV8305-Q1 gate driver uses an integrated state machine (TDRIVE) in the gate driver to protect against excessive current on the gate drive outputs, shoot-through in the external MOSFET, and dV/dt turn on due to switching on the phase nodes. The TDRIVE state machine allows for the design of a robust and efficient motor drive system with minimal overhead.

The state machine incorporates internal handshaking when switching from the low to the high-side external MOSFET or vice-versa. The handshaking is designed to prevent the external MOSFETs from entering a period of cross conduction, also known as shoot-through. The internal handshaking uses the VGS monitors of the DRV8305-Q1 to determine when one MOSFET has been disabled and the other can be enabled. This allows the gate driver to insert an optimized dead time into the system without the risk of cross conduction. Any dead time added externally through the MCU or SPI register will be inserted after the handshake process.

The state machine also incorporates a gate drive timer to ensure that under abnormal circumstances such as a short on the MOSFET gate or the inadvertent turn on of a MOSFET VGS clamp, the high peak current through the DRV8305-Q1 and MOSFET is limited to a fixed duration. This concept is visualized in the figure below. First, the DRV8305-Q1 receives a command to enable or disable the MOSFET through INHx or INLx inputs. Second, the gate driver is enabled and a strong current is applied to the MOSFET gate and the gate voltage begins to change. If the gate voltage has not changed to the desired level after the tDRIVE period (indicating a short circuit or overcurrent condition on the MOSFET gate), the DRV8305-Q1 signals a gate drive fault and the gate drive is disabled to help protect the external MOSFET and DRV8305-Q1. If the MOSFET does successfully enable or disable, after the tDRIVE period the DRV8305-Q1 will enable a lower hold current to ensure the MOSFET remains enabled or disabled and improve efficiency of the gate drive.

Select a tDRIVE time that is longer than the time needed to charge or discharge the gate capacitances of the external MOSFETs. The TDRIVE SPI registers should be configured so that the MOSFET gates are charged completely within tDRIVE during normal operation. If tDRIVE is too low for a given MOSFET, then the MOSFET may not turn on completely. It is suggested to tune these values in-system with the required external MOSFETs to determine the best possible setting for the application. A good starting value is a tDRIVE period that is 2x the expected rise or fall times of the external MOSFET gates. Note that TDRIVE will not increase the PWM time and will simply terminate if a PWM command is received while it is active.

DRV8305-Q1 TDRIVE_gate_slvsd12.gifFigure 11. TDRIVE Gate Drive State Machine