SLVSCF7B February   2014  – November 2017 DRV8308

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configurations and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 Handling Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 SPI Timing Requirements
    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  Hall Comparators
      2. 7.3.2  FG Amplifier, Comparator, and FG Output
      3. 7.3.3  Enable, Reset, and Clock Generation
      4. 7.3.4  Commutation
        1. 7.3.4.1 120° 3-Hall Commutation
        2. 7.3.4.2 120° Single-Hall Commutation
        3. 7.3.4.3 180° Sine-Wave-Drive Commutation
      5. 7.3.5  Commutation Logic Block Diagram
      6. 7.3.6  Commutation Parameters
      7. 7.3.7  Braking
      8. 7.3.8  Output Pre-Drivers
      9. 7.3.9  Current Limit
      10. 7.3.10 Charge Pump
      11. 7.3.11 5-V Linear Regulator
      12. 7.3.12 Power Switch
      13. 7.3.13 Protection Circuits
        1. 7.3.13.1 VM Undervoltage Lockout (UVLO)
        2. 7.3.13.2 VM Overvoltage (VMOV)
        3. 7.3.13.3 Motor Overcurrent (OCP)
        4. 7.3.13.4 Charge Pump Failure (CPFAIL)
        5. 7.3.13.5 Charge Pump Short (CPSC)
        6. 7.3.13.6 Overtemperature (OTS)
    4. 7.4 Device Functional Modes
      1. 7.4.1 Modes of Speed Input
        1. 7.4.1.1 Clock Frequency Mode
        2. 7.4.1.2 Clock PWM and Internal Register PWM Modes
      2. 7.4.2 Auto Gain and Advance Compensation
      3. 7.4.3 External EEPROM Mode
    5. 7.5 Programming
      1. 7.5.1 Serial Interface
      2. 7.5.2 Serial Data Format
      3. 7.5.3 Programming the OTP Configuration Memory
    6. 7.6 Register Map
      1. 7.6.1 Control Registers
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Internal Speed Control Loop Constraints
      2. 8.1.2 Hall Sensor Configurations and Connections
      3. 8.1.3 FG Amplifier Configurations and Connections
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Motor voltage
        2. 8.2.2.2 Motor Current (Peak and RMS)
        3. 8.2.2.3 Speed Command Method
        4. 8.2.2.4 Required Flutter (Speed Jitter)
        5. 8.2.2.5 Configuration Method
        6. 8.2.2.6 Hall Element Current
        7. 8.2.2.7 Power FET Switching Time
      3. 8.2.3 Application Curves
    3. 8.3 Do's and Don'ts
      1. 8.3.1 RESET and ENABLE Considerations
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    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

1 Features

  • Three-Phase Brushless DC Motor Controller
    • Digital Closed-Loop Speed Control with Programmable Gain and Filters
  • Drives 6 N-Channel MOSFETs With Configurable 10- to 130-mA Gate Drive
  • Integrated Commutation from Hall Sensors
    • Timing Can Be Advanced/Delayed
    • 120° or 180°-Sinusoidal Current Control
    • Single Input Controls Motor Speed
  • Operating Supply Voltage 8.5 to 32 V
  • Flexible Configuration Methods
    • Read Internal Non-Volatile Memory
    • Read External EEPROM
    • Write SPI
  • Configurable Motor Current Limiter
  • 5-V Regulator for Hall Sensors
  • Low-power Standby Mode
  • Integrated Overcurrent, Overvoltage, and Overtemperature Protection

2 Applications

  • Industrial Pumps, Fans, and Valves
  • White Goods
  • Power Tools and Lawn Equipment
  • Printers

3 Description

The DRV8308 controls sensored brushless DC motors with advanced features and a simple input interface. As a predriver, it drives the gates of 6 external N-Channel MOSFETs with a configurable current of 10mA to 130mA for optimal switching characteristics.

The 3 motor phases are commutated according to the Hall sensor inputs. Once the motor reaches a consistent speed, the DRV8308 uses just 1 Hall sensor to minimize jitter caused by sensor mismatch. The Hall signal-to-drive timing can be advanced or delayed in 0.1% increments to optimize power efficiency. An optional 180° commutation mode drives sinusoidal current through the motor and minimizes audible noise and torque ripple. Peak motor current can be controlled by sizing a sense resistor.

The DRV8308 achieves closed-loop speed control to spin motors to a precise RPM across a wide range of load torques. The system matches motor speed—generated from an FG trace or the Hall sensors—to the reference frequency on pin CLKIN. The DRV8308 can also drive motors open-loop using a duty cycle command, from either a clock or register setting.

An assortment of protection features bolster system robustness, as the DRV8308 handles and reports overcurrent, overvoltage, undervoltage, and overtemperature.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
DRV8308 VQFN (40) 6.00 mm × 6.00 mm
  1. For all available packages, see the orderable addendum at the end of the datasheet.

Simplified Schematic

DRV8308 simple_block.gif