A4988 DMOS Microstepping Driver: Datasheet, Pinout, and DRV8825 vs. A4988
2.087mm mm 2.79mm mm Motor Drivers 28 3.3V V 35V V 4 4.5mm mm
The A4988 is a complete micro-stepping motor driver with a built-in translator for easy operation. This post mainly covers its datasheet, pinout, typical Application Circuit and more detailed information about A4988.

How To Control a Stepper Motor with A4988 Driver and Arduino
A4988 Pinout

A4988 Pinout

A4988 Pin Circuit Diagrams
A4988 CAD Model
Symbol

A4988 Symbol
Footprint

A4988 Footprint
3D Model

A4988 3D Model
A4988 Description
The A4988 is a complete micro-stepping motor driver with a 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.
Specifications
- TypeParameter
- Factory Lead Time8 Weeks
- Mount
In electronic components, the term "Mount" typically refers to the method or process of physically attaching or fixing a component onto a circuit board or other electronic device. This can involve soldering, adhesive bonding, or other techniques to secure the component in place. The mounting process is crucial for ensuring proper electrical connections and mechanical stability within the electronic system. Different components may have specific mounting requirements based on their size, shape, and function, and manufacturers provide guidelines for proper mounting procedures to ensure optimal performance and reliability of the electronic device.
Surface Mount - Mounting Type
The "Mounting Type" in electronic components refers to the method used to attach or connect a component to a circuit board or other substrate, such as through-hole, surface-mount, or panel mount.
Surface Mount - Package / Case
refers to the protective housing that encases an electronic component, providing mechanical support, electrical connections, and thermal management.
28-VFQFN Exposed Pad - Number of Pins28
- Operating Temperature
The operating temperature is the range of ambient temperature within which a power supply, or any other electrical equipment, operate in. This ranges from a minimum operating temperature, to a peak or maximum operating temperature, outside which, the power supply may fail.
-20°C~150°C TJ - Packaging
Semiconductor package is a carrier / shell used to contain and cover one or more semiconductor components or integrated circuits. The material of the shell can be metal, plastic, glass or ceramic.
Tape & Reel (TR) - Published2005
- JESD-609 Code
The "JESD-609 Code" in electronic components refers to a standardized marking code that indicates the lead-free solder composition and finish of electronic components for compliance with environmental regulations.
e3 - Pbfree Code
The "Pbfree Code" parameter in electronic components refers to the code or marking used to indicate that the component is lead-free. Lead (Pb) is a toxic substance that has been widely used in electronic components for many years, but due to environmental concerns, there has been a shift towards lead-free alternatives. The Pbfree Code helps manufacturers and users easily identify components that do not contain lead, ensuring compliance with regulations and promoting environmentally friendly practices. It is important to pay attention to the Pbfree Code when selecting electronic components to ensure they meet the necessary requirements for lead-free applications.
yes - Part Status
Parts can have many statuses as they progress through the configuration, analysis, review, and approval stages.
Active - Moisture Sensitivity Level (MSL)
Moisture Sensitivity Level (MSL) is a standardized rating that indicates the susceptibility of electronic components, particularly semiconductors, to moisture-induced damage during storage and the soldering process, defining the allowable exposure time to ambient conditions before they require special handling or baking to prevent failures
2 (1 Year) - Number of Terminations28
- ECCN Code
An ECCN (Export Control Classification Number) is an alphanumeric code used by the U.S. Bureau of Industry and Security to identify and categorize electronic components and other dual-use items that may require an export license based on their technical characteristics and potential for military use.
EAR99 - Terminal Finish
Terminal Finish refers to the surface treatment applied to the terminals or leads of electronic components to enhance their performance and longevity. It can improve solderability, corrosion resistance, and overall reliability of the connection in electronic assemblies. Common finishes include nickel, gold, and tin, each possessing distinct properties suitable for various applications. The choice of terminal finish can significantly impact the durability and effectiveness of electronic devices.
Matte Tin (Sn) - Applications
The parameter "Applications" in electronic components refers to the specific uses or functions for which a component is designed. It encompasses various fields such as consumer electronics, industrial automation, telecommunications, automotive, and medical devices. Understanding the applications helps in selecting the right components for a particular design based on performance, reliability, and compatibility requirements. This parameter also guides manufacturers in targeting their products to relevant markets and customer needs.
General Purpose - Voltage - Supply
Voltage - Supply refers to the range of voltage levels that an electronic component or circuit is designed to operate with. It indicates the minimum and maximum supply voltage that can be applied for the device to function properly. Providing supply voltages outside this range can lead to malfunction, damage, or reduced performance. This parameter is critical for ensuring compatibility between different components in a circuit.
3V~5.5V - Terminal Position
In electronic components, the term "Terminal Position" refers to the physical location of the connection points on the component where external electrical connections can be made. These connection points, known as terminals, are typically used to attach wires, leads, or other components to the main body of the electronic component. The terminal position is important for ensuring proper connectivity and functionality of the component within a circuit. It is often specified in technical datasheets or component specifications to help designers and engineers understand how to properly integrate the component into their circuit designs.
QUAD - Peak Reflow Temperature (Cel)
Peak Reflow Temperature (Cel) is a parameter that specifies the maximum temperature at which an electronic component can be exposed during the reflow soldering process. Reflow soldering is a common method used to attach electronic components to a circuit board. The Peak Reflow Temperature is crucial because it ensures that the component is not damaged or degraded during the soldering process. Exceeding the specified Peak Reflow Temperature can lead to issues such as component failure, reduced performance, or even permanent damage to the component. It is important for manufacturers and assemblers to adhere to the recommended Peak Reflow Temperature to ensure the reliability and functionality of the electronic components.
260 - Supply Voltage
Supply voltage refers to the electrical potential difference provided to an electronic component or circuit. It is crucial for the proper operation of devices, as it powers their functions and determines performance characteristics. The supply voltage must be within specified limits to ensure reliability and prevent damage to components. Different electronic devices have specific supply voltage requirements, which can vary widely depending on their design and intended application.
3.3V - Terminal Pitch
The center distance from one pole to the next.
0.5mm - Time@Peak Reflow Temperature-Max (s)
Time@Peak Reflow Temperature-Max (s) refers to the maximum duration that an electronic component can be exposed to the peak reflow temperature during the soldering process, which is crucial for ensuring reliable solder joint formation without damaging the component.
40 - Base Part Number
The "Base Part Number" (BPN) in electronic components serves a similar purpose to the "Base Product Number." It refers to the primary identifier for a component that captures the essential characteristics shared by a group of similar components. The BPN provides a fundamental way to reference a family or series of components without specifying all the variations and specific details.
A4988 - Function
The parameter "Function" in electronic components refers to the specific role or purpose that the component serves within an electronic circuit. It defines how the component interacts with other elements, influences the flow of electrical signals, and contributes to the overall behavior of the system. Functions can include amplification, signal processing, switching, filtering, and energy storage, among others. Understanding the function of each component is essential for designing effective and efficient electronic systems.
Driver - Fully Integrated, Control and Power Stage - Number of Outputs2
- Output Voltage
Output voltage is a crucial parameter in electronic components that refers to the voltage level produced by the component as a result of its operation. It represents the electrical potential difference between the output terminal of the component and a reference point, typically ground. The output voltage is a key factor in determining the performance and functionality of the component, as it dictates the level of voltage that will be delivered to the connected circuit or load. It is often specified in datasheets and technical specifications to ensure compatibility and proper functioning within a given system.
35V - Supply Voltage-Max (Vsup)
The parameter "Supply Voltage-Max (Vsup)" in electronic components refers to the maximum voltage that can be safely applied to the component without causing damage. It is an important specification to consider when designing or using electronic circuits to ensure the component operates within its safe operating limits. Exceeding the maximum supply voltage can lead to overheating, component failure, or even permanent damage. It is crucial to adhere to the specified maximum supply voltage to ensure the reliable and safe operation of the electronic component.
5.5V - Supply Voltage-Min (Vsup)
The parameter "Supply Voltage-Min (Vsup)" in electronic components refers to the minimum voltage level required for the component to operate within its specified performance range. This parameter indicates the lowest voltage that can be safely applied to the component without risking damage or malfunction. It is crucial to ensure that the supply voltage provided to the component meets or exceeds this minimum value to ensure proper functionality and reliability. Failure to adhere to the specified minimum supply voltage may result in erratic behavior, reduced performance, or even permanent damage to the component.
3V - Number of Channels4
- Interface
In electronic components, the term "Interface" refers to the point at which two different systems, devices, or components connect and interact with each other. It can involve physical connections such as ports, connectors, or cables, as well as communication protocols and standards that facilitate the exchange of data or signals between the connected entities. The interface serves as a bridge that enables seamless communication and interoperability between different parts of a system or between different systems altogether. Designing a reliable and efficient interface is crucial in ensuring proper functionality and performance of electronic components and systems.
Logic - Output Configuration
Output Configuration in electronic components refers to the arrangement or setup of the output pins or terminals of a device. It defines how the output signals are structured and how they interact with external circuits or devices. The output configuration can determine the functionality and compatibility of the component in a circuit design. Common types of output configurations include single-ended, differential, open-drain, and push-pull configurations, each serving different purposes and applications in electronic systems. Understanding the output configuration of a component is crucial for proper integration and operation within a circuit.
Half Bridge (4) - Forward Current
Current which flows upon application of forward voltage.
1A - Supply Current-Max (Isup)
Supply Current-Max (Isup) refers to the maximum amount of current that an electronic component can draw from its power supply during operation. It represents the peak current demand of the device under normal operating conditions and is critical for ensuring that the power supply can adequately support the component's needs without risking damage or malfunction. This parameter is essential for designing circuits and selecting appropriate power supply units to prevent overloading and ensure reliable performance.
8mA - Forward Voltage
the amount of voltage needed to get current to flow across a diode.
500mV - Voltage - Load
Voltage - Load refers to the voltage across a load component in an electronic circuit when it is connected and operational. It represents the electrical potential difference that drives current through the load, which can be a resistor, motor, or other devices that consume electrical power. The voltage - load relationship is crucial for determining how much power the load will utilize and how it will affect the overall circuit performance. Properly managing voltage - load is essential for ensuring devices operate efficiently and safely within their specified limits.
8V~35V - Motor Type
Motor Type in electronic components refers to the classification or categorization of motors based on their design, construction, and operating characteristics. This parameter helps in identifying the specific type of motor being used in a particular electronic device or system. Common motor types include DC motors, AC motors, stepper motors, servo motors, and brushless motors, each with its own unique features and applications. Understanding the motor type is crucial for selecting the right motor for a given application, as different types of motors have different performance characteristics, efficiency levels, and control requirements. It is important to consider the motor type when designing or troubleshooting electronic systems to ensure optimal performance and reliability.
Stepper - Motor Type - Stepper
Motor Type - Stepper refers to a type of electromechanical device that converts electrical pulses into discrete mechanical movements. Stepper motors move in fixed angular increments or steps, allowing for precise control of position and speed. They are commonly used in applications requiring accurate positioning, such as 3D printers, CNC machines, and robotics. Stepper motors typically operate by energizing coils in a specific sequence, creating a magnetic field that moves the rotor in defined steps.
Bipolar - Step Resolution
Servo motor resolution is determined by feedback device of motor. I.e. 1000 PPR (pulses per revolution) quadrature encoder yields 1/4000 revolution resolution because 1000 PPR equals 4000 counts per revolution after standard 4X decoding.
1, 1/2, 1/4, 1/8, 1/16 - Height2.087mm
- Length4.5mm
- Width2.79mm
- REACH SVHC
The parameter "REACH SVHC" in electronic components refers to the compliance with the Registration, Evaluation, Authorization, and Restriction of Chemicals (REACH) regulation regarding Substances of Very High Concern (SVHC). SVHCs are substances that may have serious effects on human health or the environment, and their use is regulated under REACH to ensure their safe handling and minimize their impact.Manufacturers of electronic components need to declare if their products contain any SVHCs above a certain threshold concentration and provide information on the safe use of these substances. This information allows customers to make informed decisions about the potential risks associated with using the components and take appropriate measures to mitigate any hazards.Ensuring compliance with REACH SVHC requirements is essential for electronics manufacturers to meet regulatory standards, protect human health and the environment, and maintain transparency in their supply chain. It also demonstrates a commitment to sustainability and responsible manufacturing practices in the electronics industry.
Unknown - Radiation Hardening
Radiation hardening is the process of making electronic components and circuits resistant to damage or malfunction caused by high levels of ionizing radiation, especially for environments in outer space (especially beyond the low Earth orbit), around nuclear reactors and particle accelerators, or during nuclear accidents or nuclear warfare.
No - RoHS Status
RoHS means “Restriction of Certain Hazardous Substances” in the “Hazardous Substances Directive” in electrical and electronic equipment.
ROHS3 Compliant
Parts with Similar Specs
- ImagePart NumberManufacturerPackage / CaseNumber of PinsInterfaceSupply VoltageRoHS StatusMounting TypePart StatusNumber of TerminationsView Compare
A4988SETTR-T
28-VFQFN Exposed Pad
28
Logic
3.3 V
ROHS3 Compliant
Surface Mount
Active
28
28-VFQFN Exposed Pad
28
I2C, SPI, UART, USART
5 V
ROHS3 Compliant
Surface Mount
Active
28
28-VFQFN Exposed Pad
28
-
3.3 V
ROHS3 Compliant
-
Active
28
28-VQFN Exposed Pad
28
I2C, LIN, SPI, UART, USART
3.3 V
ROHS3 Compliant
Surface Mount
Active
28
32-VFQFN Exposed Pad
-
-
-
ROHS3 Compliant
Surface Mount
Obsolete
-
A4988 Features
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
A4988 Functional Block Diagram
The A4988 is a complete micro-stepping motor driver with a built-in translator for easy operation with minimal control lines. It is designed to operate bipolar stepper motors in full-, half-, quarter-, eighth, and sixteenth-step modes. The currents in each of the two output full-bridges and all of the N-channel DMOS FETs are regulated with fixed off-time PWM (pulse-width modulated) control circuitry. A functional block diagram is shown below.

A4988 Functional Block Diagram
A4988 Typical Application Circuit

A4988 Typical Application Diagram
A4988 Application Layout

A4988 Application Layout
A4988 Manufacturer
As a leading company in the development, manufacture and market of high-performance semiconductors, Allegro MicroSystems, LLC provides high-growth applications for the automotive market and also stays focus on consumer/communications, automation and industrial solutions. Headquartered in Worcester, Massachusetts (USA) Allegro locates its design, applications and sales support centres worldwide.
A4988 Package

A4988 Package
Datasheet PDF
- Datasheets :
Popularity by Region
What is A4988?
The A4988 is a complete micro-stepping motor driver with a 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.
How do I control a stepper motor with an A4988 Driver and an Arduino?
The A4988 is a micro-stepping driver for controlling bipolar stepper motors which has a built-in translator for easy operation. This means that we can control the stepper motor with just 2 pins from our controller, or one for controlling the rotation direction and the other for controlling the steps.
Where can I find A4988 stepper motor driver specifications?
It has five sets of breakout boards for Allegro’s A4988 micro stepping bipolar stepper motor driver features adjustable current limiting, over-current and over-temperature protection, and five different microstep resolutions (down to 1/16-step).lectable step modes: full, 1/2, 1/4, 1/8, and 1/16.
How do you calculate the A4988 vref?
Per the A4988 datasheet, the calculation for the maximum trip current is: I_TripMax= Vref/(8*Rs)
How do I use A4988 microstepping?
If you look at the datasheet for the A4988 you will find all the information you need. Table 2 shows how the select lines should be set for whatever level of microstepping you require:
Where can I find the A4988 Arduino library download?
A4988, DRV8825, DRV8834, DRV8880 and generic two-pin stepper motor driver library.
How do I make a stepper motor with an A4988 driver?
The A4988 is a dual H bridge with added safety features. An H Bridge is a circuit that can send power to a motor forward, backward, or not at all, based on your commands. The A4988 is dual because it has two H bridges, one for each pair of wires attached to the stepper motor. The A4988 specifically can drive up to 1 amp continuous, and up to 2 with extra cooling. The chip also handles the chore of remembering the correct sequence of H bridge changes to make your stepper motor move. You only need to tell the driver which direction and when to step.
Where can I find a heatsink for A4988 or DRV8825 stepper motor drivers?
Heatsink for A4988 or DRV8825 stepper motor drivers.
What is the maximum current for an A4988?
This stepper motor driver lets you control one bipolar stepper motor at up to 2A output current per coil (see the Power Dissipation Considerations section below for more information). Here are some of the driver’s key features.
Where can I find an A4988 wiring diagram?
I've been following this tutorial on wiring and setting up the Pololu A4988 with a small bipolar stepper motor. I have followed the directions closely, however when I get to the point where I measure the reference voltage using the potentiometer on the board I get 0. I have provided the correct wiring and a picture of mine. In my picture, I have removed the motor wires for clarity.
Is there schematic diagram of the A4988 stepper motor driver?
Schematic diagram of the A4988 stepper motor driver carrier (both green and black editions).
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