The A4915 from Allegro MicroSystems Europe is a 3-phase MOSFET motor control IC that is designed for pulse-width-modulated (PWM) current control of 3-phase brushless DC motors. The A4915 is capable of high-current gate drive for six all N-channel power MOSFETs. An internal charge pump ensures gate drive down to 7 V supply and provides limited gate drive down to 5 V. A bootstrap capacitor is used to generate a supply voltage greater than the source voltage of the high-side MOSFET: a requirement for N-channel MOSFETs. Internal synchronous rectification control circuitry with centre aligned PWM is provided to improve power dissipation in the external MOSFETs during PWM operation. Internal circuit protection includes latched thermal shutdown, dead-time protection and undervoltage lockout. Special power-up sequencing is not required. The A4915 is targeted at both the industrial and consumer markets for end applications including power tools, lawn and garden equipment, pumps, and household appliances. The A4915 is supplied in a 28-pin TSSOP with an exposed thermal pad (suffix LP) and a 28-contact 5 × 5 mm QFN with an exposed thermal pad (suffix ET). These packages are lead (Pd) free, with 100% matt tin leadframe plating. Allegro Microsystems
