Automotive 3-phase sensorless brushless DC motor controller IC



The A4960 from Allegro MicroSystems Europe is a new 3-phase sensorless brushless DC motor controller IC that incorporates extensive diagnostic and protection features. Designed for use with external N-channel power MOSFETs, the new device is ideally suited to the control of pumps, blowers and cooling fans in automotive applications. The motor drive system uses a block commutation (trapezoidal drive) approach, where phase commutation is determined, without the need for independent position sensors, by monitoring the motor back EMF. A programmable motor start-up scheme allows the A4960 to be adjusted for a wide range of motor and load combinations. External bootstrap capacitors are used to provide the voltage (above the battery supply voltage) required to drive the N-channel MOSFETs. An automatic internal bootstrap charge management scheme ensures that the bootstrap capacitor is always sufficiently charged for safe operation of the power MOSFETs. The A4960 operates over a supply voltage operating range from 7 V to 50 V, and is compatible with 3.3 V and 5 V logic. The power MOSFETs are protected from shoot-through by integrated crossover control and adjustable dead time. Integrated diagnostics provide indication of undervoltage, overtemperature and power bridge faults, and can be configured to protect the power FETs under most short-circuit conditions. Detailed diagnostics are available as a serial data word output or through a programmable diagnostic output. The A4960 is supplied in a 32-lead eLQFP package (suffix JP). This package is available in lead (Pb) free versions, with 100% matt tin lead-frame plating. Please click here to download a copy of the data sheet: About Allegro Allegro MicroSystems, Inc. is a leader in developing, manufacturing and marketing high-performance power and Hall-effect sensor integrated circuits. Allegro's innovative solutions serve high-growth applications within the automotive, communications, computer/office automation, consumer and industrial markets. Allegro is headquartered in Worcester, Massachusetts (USA) with design and applications centres located in North and South America, Asia and Europe. Further information about Allegro can be found at Allegro MicroSystems Europe, headquartered in Chertsey, United Kingdom, is the European sales and marketing operation, and operates a network of representatives and distributors throughout Europe. Allegro also has an engineering design centre in Edinburgh in Scotland and an application and marketing centre in Annecy in France.