Texas Instruments DRV8426RGER

Overview

DRV8426RGER from Texas Instruments is a fully integrated bipolar stepper motor driver IC with integrated current sensing, 1/256 microstepping indexer, STEP/DIR interface, and Smart Tune decay technology. It delivers up to 1.5-A full-scale output current (dependent on PCB thermal design), operates from 4.5 V to 33 V, and achieves ±5% full-scale current accuracy without external sense resistors. It is used in precision motion control systems such as 3D printers and automated stage lighting.

For engineers reviewing the DRV8426RGER datasheet, DRV8426RGER pinout, DRV8426RGER application, or DRV8426RGER equivalent, key selection considerations include its VQFN-24 package footprint, integrated current sensing architecture, configurable off-time (7–32 μs), smart tune vs. fixed decay mode trade-offs, and compatibility with 1.8-V/3.3-V/5.0-V logic inputs.

Technical Context

The DRV8426RGER integrates two N-channel H-bridge drivers, a microstepping indexer, and an internal current-sense architecture that replaces external shunt resistors using matched MOSFET current mirrors. Its PWM current regulation uses a voltage-controlled transimpedance gain (KV = 2.2 V/A) referenced to the VREF pin, enabling precise full-scale current setting from 0.05 V to 3.3 V.

It supports nine microstepping modes (full to 1/256) via M0/M1 pins, three decay options (Smart Tune, slow, mixed), and four programmable TOFF settings (7/16/24/32 μs). Fault management includes VM UVLO (4.25 V nominal), charge pump UVLO, overcurrent protection (2.5-A peak), and thermal shutdown (150 °C junction).

Key Specifications

Pinout & Package

VQFN-24 package (4.0 mm × 4.0 mm, 0.5-mm pitch) with exposed thermal pad; designed for compact, thermally efficient PCB layouts in space-constrained motion systems.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar stepper motor driver applications.

Compared with DRV8424RGER and DRV8436RGER, the DRV8426RGER uniquely balances 4.5–33-V operation, integrated Smart Tune decay, and VQFN-24 thermal efficiency-making it the optimal selection for mid-voltage industrial motion systems where voltage flexibility and autonomous current regulation are prioritized over absolute lowest RDS(ON) or highest voltage rating.

Availability

DRV8426RGER is available at Aetrix Electronics and suitable for 3D printers, ATM/currency handling equipment, and stage lighting systems requiring stable component supply, long-term manufacturability, and automotive-grade reliability screening.

Supply support for DRV8426RGER includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and consumer markets.

The DRV8426RGER belongs to TI's high-performance stepper motor driver product line, engineered for compact, thermally efficient, and feature-rich motion control in space- and noise-constrained applications such as office automation and medical devices.

FAQ

What is the maximum microstepping resolution supported by the DRV8426RGER?

The DRV8426RGER supports up to 1/256 microstepping via its hardware indexer, selectable using the M0 and M1 pins. This resolution is achieved without external waveform generation, enabling smooth, low-vibration motion in precision applications like 3D printing and lab automation. The DRV8426RGER maintains this capability across its full 4.5–33-V operating range and does not require firmware intervention to configure or maintain microstep accuracy.

Does the DRV8426RGER require external current sense resistors?

No, the DRV8426RGER does not require external current sense resistors. It implements an integrated current-sense architecture using matched MOSFET current mirrors, achieving ±5% full-scale current accuracy while eliminating PCB area, BOM cost, and power loss associated with external shunts. This architecture is intrinsic to the DRV8426RGER silicon design and functions identically across all supported microstepping modes and decay configurations.

How does Smart Tune decay differ from traditional decay modes in the DRV8426RGER?

Smart Tune decay in the DRV8426RGER automatically adjusts off-time and fast-decay percentage based on real-time motor behavior, voltage, and load-eliminating manual tuning required for fixed slow/mixed decay. Unlike conventional methods, Smart Tune minimizes current distortion and audible noise across varying speeds and motor types without changing external components or configuration pins. This behavior is built into the DRV8426RGER's analog control loop and operates transparently alongside its STEP/DIR interface.

What thermal derating should be applied to the DRV8426RGER's 1.5-A full-scale current rating?

The DRV8426RGER's 1.5-A full-scale current rating assumes adequate PCB thermal design (e.g., ≥400 mm² copper pour with thermal vias under the exposed pad). At 125°C ambient, full-scale current must be reduced to ~1.0 A to maintain ≤150°C junction temperature. Derating follows the RθJA = 43.0 °C/W spec; actual usable current depends on airflow, copper area, and layer stack-up-not the DRV8426RGER itself. TI provides thermal simulation models to validate layout-specific derating for the DRV8426RGER.

Can the DRV8426RGER be used with 1.8-V logic controllers?

Yes, the DRV8426RGER supports 1.8-V logic inputs on STEP, DIR, ENABLE, nSLEEP, M0, M1, DECAY0, DECAY1, and TOFF pins-verified per its recommended operating conditions (VIH = 1.5 V min, VIL = 0.6 V max). No level-shifting circuitry is needed when interfacing with 1.8-V MCUs, FPGAs, or ASICs. This compatibility is inherent to the DRV8426RGER's input structure and applies across all operating temperatures and supply voltages within its 4.5–33-V range.