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The AM4964 is highly integrated feature rich single phase Brushless Direct Current (BLDC) full wave motor driver with combined PWM and temperature speed control function for fans, blowers and extractors.
For system flexibility, the motor speed can be controlled by an external PWM signal and temperature sensed by Thermal resister at the same time. Based on external input PWM and temperature signals, the AM4964 adjusts the output PWM duty cycle. If the input PWM duty is constant, the output PWM duty varies with temperature sensed by Thermal resister sensor between the low and high temperature corners. If the temperature signal is constant, the output duty varies with the external input PWM duty. The low and high temperature corners and the output PWM duty gap between these temperature corners are adjustable
To help protect the motor coil, the AM4964 provides a rotor lock protection which shuts down the output if rotor lock is detected. The device automatically re-starts when the rotor lock is removed.
AM4964 provides a tachometer output Frequency Generator (FG). The FG output is the magnetic change frequency.
The AM4964 is available in TSSOP-20EP package.


  • Flexible Speed Control Options
    • Combined PWM+Thermistor Speed Control
    • PWM Speed Control
    • DC Voltage Speed Control
  • Adjustable Low and High Temperature Corners
  • Full Speed When Thermal Resistor is Shorted
  • Adjustable Output Duty Gap between High and Low Temperature when 100% PWM Input
  • Built-in oscillator – No external capacitor
  • Built-in Minimal Speed Setup Circuit
  • Alpha Slope Adjustable
  • Rotation Speed Indicator (FG)
  • Built-in Temperature Control Circuit
  • Built-in Thermal Shutdown Circuit
  • Lock Protection and Auto-restart
  • Totally Lead-free & Fully RoHS Compliant 
  • Halogen and Antimony Free. “Green” Device 


  • CPU Cooler Fan in PC
  • Brushless DC Motor Driver

Product Specifications

Product Parameters

Operating Voltage (V) 3.5 to 16 V
SupplyCurrent (mA) 8 mA
Average OutputDrive Current (mA) - mA
Peak Output Current (mA) 1000 mA
Reference Voltage Output (V) - V
Hall Bias Voltage (V) 1.07 V
Speed Control PWM +Temp or VDD and Slope Adjust
Speed Control Slope Adjust Yes
Minimum Speed Setting Yes
Lock Detect, Shut-Down and Auto Start Yes
Frequency Generator (FG) and Rotation Detect FG RD
Other Protection Features Thermal Shutdown
Operating Ambient Temperature (°C) -30 to 90 °C

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