Allegro MicroSystems, Inc. Announces New Full-Bridge PWM Motor Driver

With Synchronous Rectification to Lower IC Power Dissipation

February 21, 2012

A4973

Worcester, MA – Allegro announces a new full-bridge motor driver IC that is designed for bidirectional pulse width modulated (PWM) current control of inductive loads and is capable of continuous output currents to ±1.5 A and operating voltages to 50 V. Allegro’s A4973 has an internal fixed off-time PWM current-control circuitry that can be used to regulate the maximum load current to a desired value. The peak load current limit is set by the user’s selection of an input reference voltage and external sensing resistor. The fixed off-time pulse duration is set by a user-selected external RC timing network. Internal circuit protection includes thermal shutdown with hysteresis, transient suppression diodes, and crossover current protection. Special power-up sequencing is not required.

With the ENABLE input held low, the PHASE input controls load current polarity by selecting the appropriate source and sink driver pair. The MODE input determines whether the PWM current-control circuitry operates in a slow current-decay mode (only the selected source driver switching) or in a fast current-decay mode (selected source and sink switching). A user-selectable blanking window prevents false triggering of the PWM current-control circuitry. With the ENABLE input held high, all output drivers are disabled. A sleep mode is provided to reduce power consumption. When a logic low is applied to the BRAKE input, the braking function is enabled. This overrides ENABLE and PHASE to turn off both source drivers and turn on both sink drivers. The brake function can be used to dynamically brake brush DC motors.

The A4973 is supplied in a choice of two power packages; a 16-pin dual-in-line plastic package with copper heat-sink tabs, and a 16-pin plastic SOIC with copper heat sink tabs. For both package styles, the power tab is at ground potential and needs no electrical isolation. Each package type is available in a lead (Pb) free version (100% matte tin plated leadframe).



Allegro MicroSystems, LLC は、高性能半導体の開発、製造、マーケティングにおけるリーダーです。Allegro の革新的なソリューションは、自動車などの急成長している分野で広く採用されているほか、オフィス オートメーション、工業、コンシューマー/通信市場でも注目されています。Allegro の本社は米国マサチューセッツ州ウースターにあり、設計、アプリケーション、営業サポートなどの拠点を世界中に展開しています。Allegro の詳細については、www.allegromicro.com をご覧ください。

 


記事に関するお問い合わせ:

Stephanie Fennelly
マーケティング広報担当ディレクター
電話: (508) 854-5363
sfennelly@allegromicro.com
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