SLVSCX2B August   2015  – February 2016 DRV8305

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and 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 IDRIVE: Gate Driver Output Current
        2. 7.3.5.2 TDRIVE: Gate Driver State Machine
        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)
    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)
        2. 7.6.1.2 OV/VDS Faults (Address = 0x2)
        3. 7.6.1.3 IC Faults (Address = 0x3)
        4. 7.6.1.4 VGS Faults (Address = 0x4)
      2. 7.6.2 Control Registers
        1. 7.6.2.1 HS Gate Drive Control (Address = 0x5)
        2. 7.6.2.2 LS Gate Drive Control (Address = 0x6)
        3. 7.6.2.3 Gate Drive Control (Address = 0x7)
        4. 7.6.2.4 IC Operation (Address = 0x9)
        5. 7.6.2.5 Shunt Amplifier Control (Address = 0xA)
        6. 7.6.2.6 Voltage Regulator Control (Address = 0xB)
        7. 7.6.2.7 VDS Sense Control (Address = 0xC)
  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 Application Curves
  9. 9 Power Supply Recommendations
    1. 9.1 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 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

9 Power Supply Recommendations

9.1 Bulk Capacitance

Having appropriate local bulk capacitance is an important factor in motor drive system design. It is generally beneficial to have more bulk capacitance, 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
  • Power supply’s capacitance and ability to source or sink current
  • Amount of parasitic inductance between the power supply and motor system
  • Acceptable voltage ripple
  • Type of motor used (brushed DC, brushless DC, stepper)
  • Motor braking method

The inductance between the power supply and motor drive system will limit the rate current can change from the power supply. If the local bulk capacitance is too small, the system will respond 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.

DRV8305 mtr_drv_sys_lvscx2.gif Figure 23. Example Setup of Motor Drive System With External Power Supply

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