Allegro Microcontroller

We offer Allegro Microcontroller to the customers at market leading prices. The A3930 and A3931 are 3-phase brushless dc (BLDC) motor controllers for use with N-channel external power MOSFETs. Our Allegro Microcontroller incorporates much of the circuitry required to design a cost effective three-phase motor drive system, and has been specifically designed for automotive applications.

A key automotive requirement is functionality over a wide input supply range. A unique charge pump regulator provides adequate (>10 V) gate drive for battery voltages down to 7 V, and allows the device to operate with a reduced gate drive at battery voltages down to 5.5 V. Power dissipation in the charge pump is minimized by switching from a voltage doubling mode at low supply voltage to a dropout mode at the nominal running voltage of 14 V.

A bootstrap capacitor is used to provide the above-battery supply voltage required for N-channel MOSFETs. An internal charge pump for the high-side drive allows for dc (100% duty cycle) operation.