SLVSIZ2 April   2026 FAN31790

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 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 Power Supply
    6. 5.6 Fan Controller Characteristics
    7. 5.7 External Crystal Parameters
    8. 5.8 Digital IO
      1. 5.8.1 Electrical Characteristics
      2. 5.8.2 Switching Characteristics
    9. 5.9 I2C Characteristics
      1. 5.9.1 I2C Filter
      2. 5.9.2 I2C Timing Diagram
  7. 6 Detailed Description
    1. 6.1 Fan Control
      1. 6.1.1 PWM Mode
      2. 6.1.2 RPM Mode
      3. 6.1.3 Rate-of-Change Control
      4. 6.1.4 Spin-Up
      5. 6.1.5 Sequential Fan Start
      6. 6.1.6 FULL_SPEED Input
      7. 6.1.7 I2C Watchdog Timer
      8. 6.1.8 Power-on Reset Configuration Pins
    2. 6.2 Fan Monitoring
      1. 6.2.1 Tachometer Signals
      2. 6.2.2 PWM Outputs as Tachometer Inputs
    3. 6.3 Fan Faults and Failures
      1. 6.3.1 PWM Mode Failure Detection
      2. 6.3.2 RPM Mode Failure Detection
      3. 6.3.3 Locked Rotor Mode Failure Detection
      4. 6.3.4 Failure Indication
    4. 6.4 I2C Interface
      1. 6.4.1 I2C Addresses and ADDRx Pins
      2. 6.4.2 I2C Command Structure
  8. 7 Register Map
  9. 8 Register Descriptions
    1. 8.1 Global Configuration Registers
    2. 8.2 Fan Fault Registers
    3. 8.3 TACH and PWM Status Registers
    4. 8.4 PWM Duty Cycle Control Registers
    5. 8.5 TACH Target Count Registers
    6. 8.6 Window Registers
  10. 9 Application and Implementation
    1. 9.1 Typical Application
      1. 9.1.1 Schematic
      2. 9.1.2 Configuration Examples
  11. 10Device and Documentation Support
    1. 10.1 Receiving Notification of Documentation Updates
    2. 10.2 Support Resources
    3. 10.3 Trademarks
    4. 10.4 Electrostatic Discharge Caution
    5. 10.5 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information
    1. 12.1 Tape and Reel Information

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请参考 PDF 数据表获取器件具体的封装图。

机械数据 (封装 | 引脚)
  • ZFP|28
散热焊盘机械数据 (封装 | 引脚)
订购信息

6.1.1 PWM Mode

The key advantage of PWM mode is simplicity: the host directly commands the FAN31790 to output a desired speed without requiring feedback. The duty cycle for the PWMOUTx pins are configured by writing the PWM target duty cycle registers (0-511, representing 0-100%.) Each PWMOUTx channel can be individually controller. The fan's speed is proportional to the duty cycle output.

The PWM duty cycle changes gradually at a programmable rate set in the Fan Dynamics registers to minimize acoustic noise from sudden speed changes. Therefore, the actual current PWM duty cycle being output can be read anytime from the PWMOUT Duty Cycle registers.