Product category: Power Supply ICs and Controllers
News Release from: Allegro MicroSystems Europe | Subject: A3977
Edited by the Electronicstalk Editorial Team on 16 January 2002
Stepper-motor driver IC
has built-in translator
The new A3977 from Allegro MicroSystems is a stepper-motor driver IC with a built-in translator circuit for easy operation of microstepping functions
With the new device, it is only necessary to input one pulse on the step input for the motor to take one microstep. There are no phase sequence tables, high-frequency control lines or complex interfaces to program. The integration of the microstepping control functions means that the A3977 can run independent1y of a microprocessor, making it ideally suited to applications where complex processors are unavailable or over-burdened.
This article was originally published on Electronicstalk on 16 January 2002 at 8.00am (UK)
Related stories
Two motor drivers come together
Single IC provides simultaneous drive for both a DC motor and stepper motor
Switch interface needs no sense resistor
Dual-channel switch interface IC aims to simplify the implementation of two-wire Hall-effect sensor systems in automotive applications
The new IC is designed to operate bipolar stepper motors in full, half, quarter and eighth step modes, with output drive capability of 35V and +/-2.5A.
It includes a fixed-off-time current regulator that has the ability to operate in slow, fast or mixed-decay modes, automatically selected by the chopping control.
When a 'step' signal occurs, the A3977 determines if that step results in a higher or lower current in each of the motor phases.
If the change is a higher current, the decay mode is set to slow decay.
If the change is a lower current, the voltage at the 'percentage fast decay' input will set the decay mode.
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 pulsewidth-modulated (PWM) operation.
Internal circuit protection includes thermal shutdown with hysteresis, undervoltage lockout (UVLO) and crossover current protection.
Special power-up sequencing is not required.
Applications for the A3977 include the office automation, industrial and medical markets.
The inclusion of a 'sleep' mode, coupled with a 3.3-5V logic supply voltage range, makes the A3977 ideally suited to use in battery-powered equipment.
The circuit is offered in a choice of two power packages: a 44-lead plastic PLCC with a copper batwing tab and a low-profile (1.1mm) 28-lead eTSSOP with exposed power tab.
• Allegro MicroSystems Europe: contact details and other news
• Email this article to a colleague
• Register for the free Electronicstalk email newsletter
• NEW
• Electronicstalk Home Page
Related Business News
Applications/Solutions
High-performance analog ICs provide efficient, compact and dependable solutions for engine management systems, body electronics and comfort systems.
Taiwan stocks end down in biggest...
...drop in over 1 yr. Taipei, July 27 (Reuters) - Taiwan shares fell 4.22 percent on Friday to their lowest close in three weeks, marking their largest one-day percentage drop in more than a year, after a sell-off on Wall Street hurt big exporters such as TSMC .
Nippon Oil Aug refining seen flat, eyes Sudan crude
Tokyo, July 27 (Reuters) - Japan's top oil refiner Nippon Oil Corp. will keep its August processing volumes steady versus a year ago to meet summer gasoline demand and is seeking more Nile Blend crude to meet higher utility use.
Fluor Gains Eastman Chemical Gasification Plant Feed Work
Fluor Corporation announced today that it was selected by Eastman Chemical Company to provide front-end engineering and design work for a $1.6 billion gasification project along the Texas Gulf Coast.
Migao Corporation Secures Preferential Natural Gas Prices
Toronto, Ontario-- - Migao Corporation , a leading producer of specialty potash fertilizers for the Chinese market, is pleased to announce that it has negotiated preferential natural gas prices in Sichuan Province from China Petroleum & Chemical Corpora
Search the Pro-Talk network of sites
