Motor-driver IC features integrated Hall-element commutation circuitry for driving vibration motors

The new device is designed to drive low-voltage bipolar brushless DC motors, with commutation of the motor being achieved by the use of a single Hall-element sensor which detects the rotational position of an alternating-pole ring magnet.

A high-density CMOS semiconductor process allows the integration of all the necessary electronics, including the Hall-element sensor, the motor-control circuitry and the full output bridge. Low-voltage design techniques have been used to achieve device functionality down to 1.8 V drive voltage.

The A1442 is a fully integrated single-chip solution which provides enhanced reliability (including reverse battery protection and output short-circuit protection) and eliminates the need for any external support components.

A soft-switching algorithm is used to reduce audible switching noise and EMI interference. A micropower 'sleep' mode can be enabled by an external signal to reduce current consumption for battery management in portable electronic devices. This feature allows for the removal of an FET transistor for switching the device on and off.

An active function is incorporated for motor braking, which can be used to improve stop/start cycles to provide a caller ID feature in vibration mode.

The small package outline and low profile make this device ideally suited for use in applications where printed circuit board area is limited and component headroom is at a premium.

The A1442 is available in a lead (Pb) free (with nickel-palladium leadframe plating) 6-pin DFN micro-leadframe package for surface mounting, with an exposed pad for enhanced thermal dissipation. The package dimensions of 1.5 x 2 x 0.4 mm make it the lowest-profile device of its type currently available.