A3930 and A3931: Automotive 3-Phase BLDC Controller and MOSFET Driver - ALLEGRO MICROSYSTEMS - #1

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A3930 and A3931 Description The A3930 and A3931 are 3-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 speed and 3930-DS Rev. 4 Features and Benefits High current 3-phase gate drive for N-channel MOSFETs Synchronous rectification Cross-conduction protection Charge pump and top-off charge pump for 100% PWM Integrated commutation 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 Automotive 3-Phase BLDC Controller and MOSFET Driver Typical Application Continued on the next page… Package: 48 Lead LQFP with exposed thermal pad (suffix JP) Approximate Scale 1:1