Allegro MicroSytems, Inc. Announces New Single Phase Brushless DC Pre-driver IC Small Package Size with Very Few External Components

Worcester, MA ¨C February 29, 2008 ¡ª Allegro® announces the first device in a series of single-phase brushless DC motor pre-drivers used to control high current fans, blowers or pumps. Outputs are designed to drive an all N-Channel MOSFET H-Bridges with supply voltages between 8 V and 36 V. The motor speed is regulated by either a PWM (pulse width modulated) input or external analog voltage (typically thermistor). Motor speed can be monitored with the FG output and minimum speed can be programmed with an external voltage. This new device is targeted at the office automation, telecommunications, consumer and industrial markets. 
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Maximum motor current is  controlled with the internal PWM fixed off time current regulator. Synchronous rectification is employed in the PWM off cycle to reduce power dissipation. Startup current can be ramped up for reduced supply current surges and lock detection with auto restart functions reduces damage due to motor overheating. A single resistor is used to program the commutation delay to prevent shoot through and to reduce fan noise. An internal 5 V regulator is provided for the Hall element.

Protection features include thermal shutdown with hysteresis, under voltage lockout (UVLO), crossover current and locked rotor protection with auto restart. Special power up sequencing is not required.

Allegro¡¯s A4930 is supplied in a lead (Pb) free 28L QFN package (suffix ET) with exposed power tab.

About Allegro

Allegro MicroSystems, Inc. is a leader in developing, manufacturing and marketing high-performance power integrated circuits and integrated Hall-effect magnetic sensors. 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 centers located in North and South America, Asia, and Europe. Further information about Allegro can be found at www.allegromicro.com.

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