Allegro MicroSystems, Inc. Announces New DMOS Microstepping Motor Drivers With Overcurrent Protection

Small Footprint in Thermally Efficient Packages

April 29, 2010

Product Image

Worcester, MA – Allegro MicroSystems, Inc. announces the expansion of their microstepping motor driver line to include four new devices that require fewer external components and utilize a simple STEP and Direction interface. Allegro’s A4982/A4984/A4985 and A4988 devices are complete microstepping motor drivers with a built-in translator for easy operation and overcurrent protection to reduce the rework cost in both manufacturing and normal operations. They are targeted at the office automation market.

These latest devices are designed to operate bipolar stepper motors in full-, half-, quarter-, eighth and sixteenth step modes, with an output drive capacity of up to 35 V and ±2 A. They include a fixed off-time current regulator which has the ability to operate in Slow or Mixed decay modes. The translator is the key to the easy implementation of the devices. Simply inputting one pulse on the STEP input drives the motor one microstep. There are no phase sequence tables, high frequency control lines, or complex interfaces to program. The interface is an ideal fit for applications where a complex microprocessor is unavailable or is overburdened.

The chopping control automatically selects the current decay mode (Slow or Mixed). When a signal occurs at the STEP input pin, the device determines if that step results in a higher or lower current in each of the motor phases. If the change is to a higher current, then the decay mode is set to Slow decay. If the change is to a lower current, then the current decay is set to Mixed (set initially to a fast decay for a period amounting to 31.25% of the fixed offtime, then to a slow decay for the remainder of the off-time). This current decay control scheme results in reduced audible motor noise, increased step accuracy, and reduced power dissipation.

Internal synchronous rectification control circuitry is provided to improve power dissipation during PWM operation. Internal circuit protection includes: thermal shutdown with hysteresis, undervoltage lockout (UVLO), crossovercurrent, and over-current protection. Special power-on sequencing is not required.

Allegro’s A4982/A4984/A4985 and A4988 are offered in several different package options: a 28 and 32 contact 5 mm × 5 mm × 0.90 mm QFN (ET) package, a 24 contact 4.0 mm × 4.0 mm × 0.75 mm QFN (ES) package, and a 24 lead 7.8 mm × 4.4 mm × 1.2 mm eTSSOP (LP) package. All packages have exposed thermal pads for enhanced thermal dissipation, and are lead (PB) free with 100% matte tin plated lead frames.

For additional product pictures please click here:  A4984, A4985 and A4988



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
.

Copyright © 2017 Allegro MicroSystems, LLC

サイトマップ  |  個人情報保護に関する方針  |  Web マスターへのお問い合わせ

Follow us on: LinkedIn YouTube Google+ Follow Allegro on Twitter