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The AH2985 is a single-chip solution for driving two-coil brushless direct current (BLDC) fans and motors. The device includes a Hall-effect sensor, dynamic offset correction and two complementary open-drain output drivers with internal Zener diode protection. It is optimized for low start-up voltage.

To help protect the motor coils, the AH2985 provides Rotor Lock Protection which shuts down output drives if rotor lock is detected. The device automatically re-starts when the rotor lock is removed. Over temperature shutdown provides thermal protection for the device.

The AH2985 is available in TO94.


  • Two-Coil BLDC Cooling Fans
  • Low Voltage - Low Power BLDC Motors


  • Single-Chip Solution
  • Operating Voltage: 2.5V to 15V
  • Built-In Hall Sensor and Input Amplifier
  • Rotor Lock Protection (Lock Detection, Output Shutdown and Automatic Re-Start)
  • Built-In Reverse Voltage Protection Diode
  • Built-In Zener Protection for Output Drivers
  • Average Output Current up to 500mA
  • Package: TO94
  • “Green” Molding Compound
  • Totally Lead-Free & Fully RoHS Compliant
  • Halogen and Antimony Free. “Green” Device

Product Specifications

Product Parameters

Operating Voltage 2.5 to 15 V
Supply Current 3.5 mA
Average Output Drive Current 500 mA
Peak Output Current 800 mA
Typical Total RDS(ON) (NMOS and PMOS Combined) - Ω
Typical Zener Breakdown Voltage - V
Grade -
Operating Point Bop Gauss (Min) 5
Operating Point Bop Gauss (Typ) 30
Operating Point Bop Gauss (Max) 60
Release Point Brp Gauss (Min) -60
Release Point Brp Gauss (Typ) -30
Release Point Brp Gauss (Max) -5
Lock Detect, Shut-Down and Auto Start -
Frequency Generator (FG) and Rotation Detect RD RD
Operating Ambient Temperature -40 to 105 °C

Related Content

Quality Documentation

Technical Documents

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Orderable Part Number Authorized Distributor Quantity Inventory Date Buy Online Region
AH2985-P-B Digi-Key Electronics 824 8/8/2020 Buy Now United States
AH2985-P-B Mouser Electronics Inc. 815 8/8/2020 Buy Now United States


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