HR4988 Overview
The HEROIC HR4988 is a bipolar microstepping stepper motor driver IC incorporating a built-in translator that dramatically simplifies the interface between a host microcontroller and a two-phase stepper motor. Rather than requiring the MCU to manage the complex multi-phase current sequencing needed for microstepping, the HR4988’s internal translator reduces motor control to two simple inputs — STEP and DIR — where each pulse on the STEP pin advances the motor by one step in the direction set by the DIR pin. Step resolution is configured via the MSx logic input pins, selecting full-, half-, 1/4-, 1/8-, or 1/16-step operation to suit the precision and torque requirements of the application.
HEROIC’s HR4988 delivers an output drive capability of 32V and ±2A, covering a wide range of bipolar stepper motors used in desktop manufacturing equipment, laboratory automation, and precision positioning systems. The device features an internal synchronous rectification control circuit that reduces power dissipation during PWM current regulation — improving thermal performance compared to conventional diode-based recirculation approaches. The control logic supply (VControl) accepts 3V to 5.5V, providing direct compatibility with 3.3V ARM Cortex and ESP32-class microcontrollers as well as 5V AVR and PIC platforms, without level-shifting circuitry. No special power-up sequencing is required, further simplifying firmware development.
The HR4988 integrates a full protection suite — thermal shutdown with hysteresis, undervoltage lockout (UVLO), and overcurrent protection (OCP) — reducing the need for external protection components and enhancing system reliability in unattended operation. The device is housed in a compact QFN-28 (5.0mm × 5.0mm) package with an exposed thermal pad that transfers heat efficiently to the PCB, supporting higher continuous current operation. The HR4988 is a lead-free, RoHS-compliant product. ABL Semi stocks the HR4988 as a fully authentic HEROIC factory product, with flexible MOQ for prototyping and volume production, and serves as a direct pin-to-pin alternative to the widely deployed Allegro A4988.
Key Specifications
| Parameter | Value |
|---|---|
| Device Type | Bipolar Microstepping Stepper Motor Driver with Translator |
| Motor Supply Voltage | Up to 32V |
| Output Current (Peak) | ±2A per phase |
| On-Resistance RDS(on) | 640mΩ (per FET) |
| Control Logic Supply (VControl) | 3V to 5.5V |
| Step Resolution Modes | Full, 1/2, 1/4, 1/8, 1/16 step |
| Step Mode Selection | MSx logic input pins |
| Control Interface | STEP / DIR (translator built-in) |
| PWM Current Control | Internal synchronous rectification |
| Protection Features | Thermal shutdown (with hysteresis), UVLO, OCP |
| Power-Up Sequencing | Not required |
| Package | QFN-28 (5.0mm × 5.0mm) with exposed thermal pad |
| Compliance | RoHS compliant, lead-free |
Applications
The HR4988 is designed for precision motion control applications where accurate, low-vibration bipolar stepper motor drive is required from a compact, easy-to-integrate IC. Primary application areas include FDM 3D printers, CNC router and milling machines, laser engravers, pick-and-place equipment, and laboratory liquid handling systems. The device is equally well-suited to CCTV pan-tilt camera platforms, optical lens focus actuators, and industrial conveyor positioning systems, where its 1/16-step microstepping capability delivers smooth, precise motion with minimal resonance and audible noise.
Pin-to-Pin Compatible Alternatives
The HR4988 shares the same QFN-28 (5×5mm) footprint and STEP/DIR/MSx control interface as the industry-dominant Allegro A4988, enabling a direct, zero-modification board-level substitution that immediately reduces BOM cost and provides supply chain redundancy for high-volume production programmes.
| Reference Part Number | Original Manufacturer | Why Choose HR4988 |
|---|---|---|
| A4988 | Allegro MicroSystems | The industry-standard 1/16-step bipolar stepper driver; HR4988 is a direct pin-for-pin replacement in the same QFN-28 footprint, offering equivalent functionality at a lower unit cost with flexible MOQ from ABL Semi |
| DRV8825 | Texas Instruments | Popular 1/32-step stepper driver in QFN-28; HR4988 is a cost-effective alternative for designs where 1/16-step resolution is sufficient, with identical STEP/DIR control interface for effortless firmware reuse |
| TB67S249FTG | Toshiba | Advanced microstepping driver with similar bipolar drive capability; HR4988 provides a simpler integration path with no power-up sequencing requirement and a directly compatible package footprint |
| STSPIN220 | STMicroelectronics | Low-voltage stepper driver in QFN format; HR4988 supports a wider motor supply voltage up to 32V, making it better suited to 24V industrial and desktop manufacturing stepper motor applications |
Frequently Asked Questions
Is HR4988 RoHS compliant?
Yes. The HR4988 is fully RoHS compliant and lead-free. HEROIC manufactures the HR4988 in accordance with EU RoHS Directive 2011/65/EU, ensuring the device is free from restricted hazardous substances including lead and mercury. ABL Semi can provide full compliance and trade documentation upon request to support UK and European regulatory and procurement requirements.
What are the pin-to-pin replacements for HR4988?
The HR4988 is a direct pin-compatible replacement for the Allegro A4988 — the most widely deployed bipolar microstepping driver in desktop manufacturing and automation — and is functionally compatible with the Texas Instruments DRV8825, Toshiba TB67S249FTG, and STMicroelectronics STSPIN220 in the same QFN-28 package format. Refer to the compatibility table above for a detailed comparison of each alternative.
What is the minimum order quantity (MOQ) for HR4988?
ABL Semi offers flexible MOQ for HR4988, supporting both prototype quantities and mass production orders. Contact us for current stock and pricing.
What package options are available for HR4988?
The HR4988 is available in a QFN-28 (5.0mm × 5.0mm) package with an exposed thermal pad on the underside. The thermal pad should be soldered directly to a PCB copper pour connected to the ground plane, providing the primary heat dissipation path and allowing the HR4988 to sustain higher continuous output currents in typical PCB layouts. This package is pin-compatible with the Allegro A4988 QFN-28, enabling direct board-level replacement. Contact ABL Semi to confirm current stock availability.
How do I set the current limit on the HR4988?
The HR4988’s output current limit is set by an external reference voltage applied to the VREF pin, in combination with the value of external current sense resistors placed in series with each motor output. The relationship follows the standard formula: Itrip = VREF / (8 × Rsense). A trimmer potentiometer connected between the supply voltage and GND — with the wiper connected to VREF — is the most common implementation, allowing the current limit to be adjusted without firmware changes. For accurate current setting, measure the VREF voltage directly at the pin with a multimeter rather than relying on potentiometer position, as component tolerance can introduce significant variation. Setting the current limit correctly is important both for motor torque and for preventing thermal overload of the HR4988 and the motor windings.
For complete product specifications, please refer to: