Allegro MicroSystems A89211/12 & AD89211-A/12-A 32-Bit MCUs

Allegro MicroSystems A89211/12 and AD89211-A/12-A 32-Bit Microcontrollers (MCUs) are high-performance processors with integrated three-phase gate drive and precision current sense capability. Engineers designed the A89211/12 and AD89211-A/12-A for advanced, stand-alone, three-phase BLDC and PMSM motor control applications.

The processor uses an Arm® Cortex®-M4 CPU core running at 40MHz, delivering up to 50MIPS performance. Peripheral functions specifically designed for motor control applications further enhance the processor's capabilities. These include a PWM generator and a sense current capture system capable of providing up to 12-bit control precision at a PWM frequency of up to 20kHz.

Sixteen general-purpose I/O ports provide access to programmable serial communication interfaces and analog and digital inputs and outputs. The N-channel power MOSFET gate driver controls MOSFETs in a three-phase bridge arrangement. It specifically targets high-power inductive loads, such as BLDC motors.

A unique charge pump regulator provides the MOSFET gate-drive supply for battery voltages as low as 7V and allows the A89211/12 and AD89211-A/12-A to operate with reduced gate-drive voltage as low as 5.5V. A bootstrap capacitor provides the supply voltage above the battery voltage required for N-channel MOSFETs.

The power supply unit provides and manages all internal supplies from a single 5.5V to 60V (A89211/11-A) or 5V to 90V (A89212/12-A) supply. Integrated programmable diagnostics indicate multiple internal, system, and power bridge faults. The user can configure the diagnostics to protect the power MOSFETs under most short-circuit conditions.

Allegro MicroSystems supplies the A89211/12 and AD89211-A/12-A in a 48-lead QFN package featuring an exposed thermal pad and wettable flank. This package is lead (Pb) free with 100% matte-tin lead frame plating.

Features

  • 5.5V to 90V supply voltage operating range
  • 60V part variant available (A89211/A89211-A)
  • 32-bit Arm Cortex-M4 CPU core
    • Up to 40MHz clock frequency
    • On-chip ±1% accurate oscillator
    • Programmable clock generator
    • One clock per machine cycle architecture
    • Direct memory access (DMA)
    • 16-level interrupt handler
    • SW-DP 2-wire debug
  • On-chip memory
    • Up to 252kB Flash
    • 32kB DRAM
    • 8kB IRAM
    • 32kB boot ROM
  • 3-phase bridge MOSFET driver with bootstrap gate drive for N-channel MOSFET bridge
  • Charge pump for low supply voltage operation
  • 3.3V or 5V CMOS compatible logic I/O
  • 80MHz PWM generator
    • 12-bit PWM at 20kHz
    • Programmable Back Electro-Motive Force (BEMF) and current sample control
  • Programmable high-performance current sense amplifier (3x 11-bit, 1µs ADCs for current measurement)
  • 12-bit 1µs data acquisition ADC with 16-channel mux
  • Eight general-purpose I/O ports (GPIO)
  • Eight general-purpose timers
  • Two serial communication interfaces (SCI)
  • 3-phase BEMF detector
  • Integrated power management
  • VDS, UVLO, and thermal shutdown diagnostic
  • Latched TSD with fault output

Applications

  • Optimized for 12V to 56V battery BLDC motor modules
  • Cordless power tools
  • 48V e-bikes

Block Diagram

Block Diagram - Allegro MicroSystems A89211/12 & AD89211-A/12-A 32-Bit MCUs
Published: 2026-05-13 | Updated: 2026-05-19