A3931 Datasheet | Allegro MicroSystems

FEATURES AND BENEFITS - High current three-phase gate drive for N-channel MOSFETs - Synchronous rectification - Cross-conduction protection - Charge pump and top-off charge pump for 100% PWM - Integrated mutation decoder logic - Operation over 5.5 to 50 V supply voltage range - Extensive diagnostics output - Provides +5 V Hall sensor power - Low-current sleep mode PACKAGE: 48-Lead LQFP with exposed thermal pad (suffix JP) Not to scale DESCRIPTION The A3930 and A3931 are three-phase brushless DC (BLDC) motor controllers for use with N-channel external power MOSFETs. They incorporate much of the circuitry required to design a cost-effective three-phase motor drive system and have 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. Internal fixed-frequency PWM current control circuitry can be used to regulate the maximum load current. The peak load current limit is set by the selection of an input reference voltage and external sensing resistor. The PWM frequency is set by a user-selected external RC timing network. For added flexibility, the PWM input can be used to provide Continued on the next page… Typical Application 3930-DS, Rev. 8 MCO-0000483 October 15, 2024 A3930 and A3931 Automotive 3-Phase BLDC Controller and MOSFET Driver DESCRIPTION (CONTINUED) speed and torque control, allowing the internal current control...