New family of complete microstepping motor driver ICs

simple step and direction interface makes microstepping easy and accurate

Allegro MicroSystems Europe has introduced a new family of complete microstepping motor driver ICs with built-in translators.

Allegro’s A5976, A5977 and A5979 have been designed to operate bipolar stepper motors in full-, half-, quarter-, eight, (A5977) and sixteenth- (A5976/79) step modes. All have the output drive capability of 40 V and ±2.8 A and include a fixed off-time current regulator that has the ability to operate in slow, fast, or mixed-decay modes. This current-decay control scheme results in reduced audible motor noise, increased step accuracy, and reduced power dissipation.

These new devices are targeted at the office automation and industrial automation markets including textile and sewing machines, vending machines, printers, scanners, copiers, closed circuit TV camera positioning, ATM machines, 3D printing systems, and food industry applications.

The translator is the key to the easy implementation of these devices. Simply inputting one pulse on the STEP input drives the motor one step or microstep (two logic inputs determine if it is a full-, half-, quarter-, eighth- or sixteenth-step resolution). 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 overburdened.

Internal synchronous rectification control circuitry is provided to improve power dissipation during PWM operation. Internal circuit protection includes OCP (overcurrent protection) thermal shutdown with hysteresis, undervoltage lockout (UVLO), and crossover-current protection. An open-drain FAULT output is included in the A5976 for improved diagnostic reporting. Special power-up sequencing is not required.

All three devices are supplied in a thin (<1.2 mm) 28-pin TSSOP with an exposed thermal pad (suffix LP) for enhanced thermal dissipation. The package is lead (Pb) free (suffix -T), with 100% matt-tin leadframe plating. Operating ambient temperature range is -40°C to 105°C.

About Allegro

Allegro MicroSystems, LLC is a leader in developing, manufacturing and marketing high-performance semiconductors. Allegro's innovative solutions serve high-growth applications within the automotive market, with additional focus on office automation, industrial, and consumer/communications solutions. Allegro is headquartered in Worcester, Massachusetts (USA) with design, applications, and sales support centers located worldwide. Further information about Allegro can be found at www.allegromicro.com

Allegro MicroSystems Europe, headquartered in Chertsey, United Kingdom, is the European sales and marketing operation, and operates a network of representatives and distributors throughout Europe.  Allegro also has an engineering design centre in Edinburgh in Scotland and an application and marketing centre in Annecy in France.