A3930_16 Datasheet, PDF (1/21 Pages) Allegro MicroSystems – Automotive 3-Phase BLDC Controller and MOSFET Driver

A3930 and A3931
Automotive 3-Phase BLDC Controller and MOSFET Driver
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
Package: 48 Lead LQFP with exposed
thermal pad (suffix JP)
Approximate Scale 1:1
Description
TheA3930 andA3931 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
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Typical Application
3930-DS Rev. 4