AMT49413: High Power BLDC MOSFET Controller with Integrated Hall Commutation

The AMT49413 is a three-phase brushless DC motor controller for use with N-channel external power MOSFETs designed for automotive and industrial applications. The AMT49413 includes the required logic to spin a motor without any code— facilitating shorter design cycles.

The AMT49413 is designed to operate across a wide voltage range, including automotive applications up to 50V. 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 torque control, allowing the internal current control circuit to set the maximum current limit.

Efficiency is enhanced by using synchronous rectification. A full suite of protection features is provided including MOSFET crossover control with dead time, undervoltage, overvoltage, HALL logic fault, low motor current and short to ground, supply and across motor winding. The dead time can be set by a single external resistor. Allegro recommended hall latches: APS13290-1.

The AMT49413 is supplied in a 48-pin QFN with exposed thermal pad and is available in a wettable flank for automotive applications. This is a small footprint (49 mm2) power package providing nearly a 40% footprint reduction compared to an equivalent QFP package.