A4988 DMOS Microstepping Driver
A4988: DMOS Microstepping Driver with Translator and Overcurrent Protection
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.
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), and crossover-current protection. Special power-on sequencing is not required.
The A4988 is supplied in a surface mount QFN package (ET), 5 mm × 5 mm, with a nominal overall package height of 0.90 mm and an exposed pad for enhanced thermal dissipation. It is lead (Pb) free (suffix –T), with 100% matte tin plated leadframes.
|Operating Supply Current
|Operating Supply Voltage
|-20 °C ~ 150 °C(TJ)
|8V ~ 35V
|28-contact QFN with exposed thermal pad 5×5 mm × 0.90 mm (ET package)
Allegro Micro Systems
A33115 Precision TMR Angle Sensor
360° angle sensor that provides high-resolution angular position information.
Integrated shield virtually eliminates capacitive coupling from current conductor to die, greatly suppressing output noise due to high dv/dt transients.
A31010 Unidirectional Linear Hall-Effect Sensors
Provide a voltage output proportional to the applied magnetic field.
A89506 Full-Bridge PWM Gate Driver
Ideal for DC motors and actuators in conventional, hybrid, and electric vehicles.
Brushless DC Drivers
Engineered to meet market challenges, delivering cost-optimized systems and improved time-to-market.
Brush DC Drivers
Broad portfolio of safe and robust brush DC solutions with both integrated and MOSFET gate drivers.
Stepper Motor Drivers
Delivers quiet, efficient, smooth motion to minimize noise and vibration in stepper motor designs.
Sensor Interface ICs
Allegro’s interface sensor ICs for speed and pressure sensors deliver fast and accurate output ideal for today’s demanding, space-constrained automotive and industrial applications.
Allegro’s multiple-output DC/DC regulators enable smart and robust industrial designs.