A4931METTR-T

Overview

The A4931METTR-T is a three-phase brushless DC (BLDC) motor pre-driver manufactured by Allegro MicroSystems. It operates within a supply voltage range of 8V to 37.5V and supports peak output currents up to 30mA. The device features an integrated 3.3V/5V regulator and functions as a half-bridge driver for external N-channel MOSFETs. It includes protection mechanisms such as stall detection, thermal shutdown, and overvoltage monitoring. The component is housed in a compact 28-pin QFN package with dimensions of 5mm x 5mm and an exposed thermal pad, suitable for surface mount applications across a temperature range of -20°C to +105°C.

Feature Summary

• Synchronous rectification technology reduces power loss during current decay phases by conducting appropriate MOSFETs.
• Integrated commutation logic utilizes three 120-degree spaced Hall sensor inputs to manage motor direction and phase sequencing.
• Built-in fixed off-time PWM current control limits surge currents while providing adjustable stall protection with configurable delay.
• Dedicated fault output pins provide precise speed measurement signals that switch states during Hall effect transitions.

Applications

• Three-phase BLDC motor control systems
• Fan and pump speed regulation circuits
• Industrial automation actuators
• Consumer appliance motor drives

Procurement Notes

Verify the manufacturer part number A4931METTR-T against official Allegro MicroSystems documentation to ensure authenticity. Confirm the specific suffix indicates the tape and reel packaging format. Check for RoHS compliance status and moisture sensitivity level ratings prior to integration into assembly processes.

Selection Notes

Select this component when designing compact three-phase BLDC motor drivers requiring integrated commutation logic. It is suitable for applications needing synchronous rectification to improve efficiency. Ensure the external MOSFET selection matches the voltage and current requirements supported by the pre-driver interface.

Part Context

This part belongs to the A4931 family of motor controllers designed for efficient motion control solutions. It serves as a pre-driver stage, managing gate drive signals for external power stages rather than containing integrated high-current power FETs internally. The design focuses on reducing system complexity by integrating Hall sensing interfaces and protection features.

Replacement Considerations

Evaluate the APEK4931MET-01-T-DK evaluation board for functional verification if testing replacement units. Consult official Allegro MicroSystems documentation for any direct pin-to-pin compatible alternatives within the same product family before substitution.

FAQ

How does the A4931 handle current limiting?

It employs fixed off-time PWM current control to restrict surge currents during operation.

What input signals determine motor commutation?

Commutation is determined by three Hall element inputs spaced 120 degrees apart.

Does the device support synchronous rectification?

Yes, it uses synchronous rectification to lower power consumption by shorting low RDS MOSFETs with body diodes during current decay.