Integrated Sensorless FOC BLDC Driver


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The AMT49400 is an advanced 3-phase, sensorless, brushless DC (BLDC) motor driver with integrated power MOSFETs.

A minimal application circuit can be achieved with only two external components due to device’s high level of integration, which includes control algorithm, analog circuit, and power stage.

A field-oriented control (FOC) algorithm is fully integrated to achieve the best efficiency and acoustic noise performance. EEPROM programmability is included to optimize motor startup performance.

The motor speed is controlled by applying a duty cycle command to the PWM input. A simple I2C interface is provided for setting motor-rated voltage, rated current, rated speed, resistance, and startup profiles. The I2C interface is also used for on/off control, speed control, and speed readback.

The AMT49400 is available in a very small 10-lead SOIC with exposed pad, (suffix LK).

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  • Coding-free sensorless field-oriented control (FOC)
  • Standby mode current less than 10 μA
  • Quiet and quick startup
  • Only two external components for minimal application circuit
  • PWM speed input, FG speed output
  • Lock detection
  • Soft-on soft-off (SOSO)
  • Optional closed-loop speed control
  • Configurable current limit
  • Windmill and reverse windmill operation
  • Lock detection
  • Short-circuit protection (OCP)

Typical Applications:

  • All-in-One PC and Laptop Cooling Fan
  • Exhaust & Graphical Cooling Fans
  • Home Appliance Fans & Pumps
  • Server Cooling Fan
10-lead SOIC with exposed thermal pad (LK package)

LK Package Documentation

Part Number Specifications and Availability

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PWR Meter 3 Demo Board

Brushless 21 Click is a compact add-on board suitable for controlling brushless DC (BLDC) motors with any MCU. This board features the AMT49400, an advanced 3-phase, sensorless BLDC motor driver with integrated power MOSFETs from Allegro Microsystems

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