A4988 Ver la hoja de datos (PDF) - Allegro MicroSystems

Número de pieza

componentes Descripción

Lista de partido

A4988

DMOS Microstepping Driver with Translator and Overcurrent Protection / 28-contact QFN

Allegro MicroSystems 

A4988

DMOS Microstepping Driver with Translator

And Overcurrent Protection

Features and Benefits

▪ Low RDS(ON) outputs

▪ Automatic current decay mode detection/selection

▪ Mixed and Slow current decay modes

▪ Synchronous rectification for low power dissipation

▪ Internal UVLO

▪ Crossover-current protection

▪ 3.3 and 5 V compatible logic supply

▪ Thermal shutdown circuitry

▪ Short-to-ground protection

▪ Shorted load protection

▪ Five selectable step modes: full, 1/2, 1/4, 1/8, and 1/16

Package:

28-contact QFN

with exposed thermal pad

5 mm × 5 mm × 0.90 mm

(ET package)

Description

The A4988 is a complete microstepping motor driver with

built-in translator for easy operation. It is 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. The A4988 includes 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

A4988. 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 A4988 interface is an ideal fit for applications where a

complex microprocessor is unavailable or is overburdened.

During stepping operation, the chopping control in the A4988

automatically selects the current decay mode, Slow or Mixed.

In Mixed decay mode, the device is set initially to a fast decay

for a proportion of the fixed off-time, then to a slow decay for

the remainder of the off-time. Mixed decay current control

results in reduced audible motor noise, increased step accuracy,

and reduced power dissipation.

Approximate size

Continued on the next page…

Microcontroller or

Controller Logic

Typical Application Diagram

VDD

0.22 µF

0.1 µF

0.1 µF

0.22 µF

5 kΩ

VREG ROSC CP1 CP2 VCP VBB1

VDD

VBB2

SLEEP

STEP

MS1

MS2

MS3

DIR

ENABLE

RESET

VREF

A4988

OUT1A

OUT1B

SENSE1

GND

OUT2A

OUT2B

SENSE2

GND

4988-DS, Rev. 5

100 µF

Share Link: