Allegro MicroSystems A3930
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. The A3930 and A3931 only differ in their response to the all-zero combination on the Hall inputs.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 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 PACKAGE: 48-Lead LQFP with exposed thermal pad (suffix JP) Not to scale
DESCRIPTION
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.