A new sensorless BLDC controller has been announced by Allegro MicroSystems, which is the most advanced solution on the market today. Allegro’s automotive version of the A5932 is a three-phase BLDC motor controller solution that is targeted at high-power automotive fan applications with very low vibration and audible noise requirements. MOSFET gate driver outputs permit motor currents that can be scaled to fit the applications requirements.
A user friendly GUI interface means fast evaluation and a shorter time to market. Key automotive applications include seat, battery, infotainment and headlamp cooling fans.
The motor speed is controlled by applying a duty cycle command to the speed (SPD) input. The SPD input is allowed to operate over a wide frequency range. A sinusoidal voltage profile is applied to the windings of the motor at startup to quietly start up and gradually ramp up the motor to the desired speed. This new device has a 5.5-50 input voltage rating with an operating range of -40 to 150°C.
The A5932 is available in a 24-contact 4×4mm QFN with exposed thermal pad (suffix ES), and a 24-lead TSSOP with exposed thermal pad (suffix LP). The QFN package is supplied in a wettable flank allowing visual PCB solder inspection. These packages are lead (Pb) free, with 100% matt-tin leadframe plating.