A4983SETTR-T - 35V/±2A DMOS Microstepping Driver | Allegro
MPN: A4983SETTR-T ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.45 | $2.45 |
| 10 | $2.18 | $21.80 |
| 100 | $1.85 | $185.00 |
| 500 | $1.62 | $810.00 |
| 1,000 | $1.45 | $1,450.00 |
| 3,000 | $1.21 | $3,630.00 |
A4983SETTR-T Overview
A stepper motor driver is an integrated power IC that translates digital step/direction inputs into precisely controlled phase currents in a bipolar stepper motor. The A4983 belongs to the DMOS microstepping driver family — DMOS (Double-Diffused Metal-Oxide Semiconductor) outputs that combine the high current capability of bipolar transistors with the ease-of-drive of MOSFET gates. Within the broader taxonomy, it is a stepper motor driver > motor driver IC > power management IC > semiconductor. The built-in translator eliminates the host microcontroller's burden of generating complex phase timing waveforms.
Key specifications include 35 V absolute maximum load supply, ±2 A continuous phase current (with proper PCB thermal design), synchronous rectification for low power dissipation, automatic current-decay mode detection/selection (Mixed and Slow decay modes), an internal fixed off-time PWM current regulator, internal UVLO (undervoltage lockout) on the logic and motor rails, and a logic supply range compatible with 3.3 V and 5 V MCUs. The QFN-28 (5x5) package features an exposed thermal pad that must be soldered to a sufficient copper pour for heat extraction.
Architecturally, the A4983 combines a serial-step translator, a dual H-bridge DMOS output stage, a precision current-sense comparator, and synchronous rectification control. The translator accepts STEP and DIR inputs from the host MCU and increments the internal H-bridge logic through the chosen microstep table. The current regulator uses an external sense resistor (RSENSE) to chop the phase current at the user-set peak, with automatic decay-mode selection optimizing zero-crossing behavior in mid-range microsteps. Synchronous rectification reduces body-diode conduction losses by actively turning on the low-side DMOS during current recirculation.
Typical applications include 3D printers (replacing or supplementing A4982/A4988 designs), small CNC machines, robotics actuator drivers, automated textile machinery, and laboratory automation steppers. The 1/16-step resolution and ±2 A drive capacity are also well-matched to NEMA 17 bipolar steppers in low-voltage (12-24 V) systems.
When designing with this part, ensure the exposed thermal pad is soldered to a copper pour of at least 1 square inch, the sense resistor is sized for the desired peak phase current using ITRIP = VREF / (8 × RSENSE), and the logic supply (VDD) is decoupled with a 100 nF ceramic close to the pin. Decay-mode selection must be tested under load; Mixed decay is the typical default but Slow decay may be preferred for low-inductance motors.
This page synthesizes distributor pricing, drop-in cross-references, and application design notes not consolidated in the manufacturer datasheet.
Drop-in alternatives for A4983SETTR-T — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
A4982SETTR-T
✅ Drop-In📋 Reference alternative (not in catalog)
A4988SETTR-T
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A4983SET-T
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A4984SETTR-T
✅ Drop-In📋 Reference alternative (not in catalog)
DRV8835DRCTR
✅ Drop-In📋 Reference alternative (not in catalog)
A4983SETTR-T Maximum Ratings & Electrical Characteristics
| Motor Type | Bipolar stepper motor |
| Output Configuration | Dual H-bridge (DMOS) |
| Load Supply Voltage (VMOT) | 8 V to 35 V absolute max |
| Logic Supply Voltage (VDD) | 3.0 V to 5.5 V |
| Continuous Phase Current | ±2 A (with proper PCB thermal design) |
| Microstep Resolution | Full, 1/2, 1/4, 1/8, 1/16 step |
| Built-in Translator | Yes (STEP/DIR interface) |
| Current Decay Modes | Automatic Mixed / Slow decay selection |
| Synchronous Rectification | Yes (low-side DMOS active during decay) |
| Undervoltage Lockout (UVLO) | Internal (logic and motor rail) |
| Low RDS(ON) Outputs | Yes (DMOS) |
| Current Regulation | Fixed off-time PWM with external RSENSE |
| Package | 28-pin QFN (5x5 mm) with exposed thermal pad |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant (lead-free) |
A4983SETTR-T Pin Configuration
| Pin 1 | CP1 — Charge pump capacitor terminal 1 |
| Pin 2 | CP2 — Charge pump capacitor terminal 2 |
| Pin 3 | VCP — Charge pump reservoir (high-side supply) |
| Pin 4 | VREG — Internal regulator decoupling |
| Pin 5 | MS1 — Microstep select bit 1 |
| Pin 6 | MS2 — Microstep select bit 2 |
| Pin 7 | MS3 — Microstep select bit 3 |
| Pin 8 | RST — Reset input (active low) |
| Pin 9 | SLP — Sleep mode input (active low) |
| Pin 10 | VDD — Logic supply (3.0-5.5 V) |
| Pin 11 | GND — Logic / analog ground |
| Pin 12 | STEP — Step input (rising edge advances) |
| Pin 13 | DIR — Direction input |
| Pin 14 | EN — Enable input (active low) |
| Pin 15 | ROSC — Oscillator timing (off-time) |
| Pin 16 | VREF — Current set reference voltage |
| Pin 17 | 1B — Phase 1 B-output (motor coil 1B) |
| Pin 18 | 1A — Phase 1 A-output (motor coil 1A) |
| Pin 19 | SENSE1 — Phase 1 current sense resistor |
| Pin 20 | 2A — Phase 2 A-output (motor coil 2A) |
| Pin 21 | 2B — Phase 2 B-output (motor coil 2B) |
| Pin 22 | SENSE2 — Phase 2 current sense resistor |
| Pin 23 | VMOT — Motor supply (8-35 V) |
| Pin 24 | NC — Not connected (per datasheet) |
| Pin 25 | NC — Not connected (per datasheet) |
| Pin 26 | NC — Not connected (per datasheet) |
| Pin 27 | NC — Not connected (per datasheet) |
| Pin 28 | NC — Not connected (per datasheet) |
Typical Applications
A4983SETTR-T is suitable for 7 applications: 3D Printer Stepper Driver, Small CNC Mill / Router, Robotics Servo Motor Driver, Automated Textile / Sewing Machine, Laboratory Automation Pipette / Syringe Pump, Camera Slider / Pan-Tilt Head, Desktop Laser Engraver.
3D Printer Stepper Driver
The A4983SETTR-T fits the X/Y/Z axis stepper driver role on a 3D printer motherboard because of its 35 V VMOT rating, ±2 A phase current, and 1/16-step microstepping. With VMOT typically set to 12-24 V, it comfortably drives NEMA 17 steppers at the standard 1.5 A peak per phase. The built-in STEP/DIR translator accepts direct GPIO pulses from an 8-bit MCU (Atmel/Microchip) without generating phase tables, and the automatic Mixed/Slow decay mode keeps microstep transitions clean at high step rates. Compared to the TI DRV8835, the A4983 handles higher voltage for the same footprint, enabling hotter extruders and faster print speeds. Design tip: use a 200 mΩ RSENSE for 1.5 A peak and add 100 nF + 10 µF VMOT decoupling near the IC.
Recommended
Small CNC Mill / Router
The A4983SETTR-T is widely used in hobbyist CNC routers and small mills to drive NEMA 17 / NEMA 23 axis motors from 24 V supplies. The 35 V headroom allows VMOT to be set near 24 V for higher torque at high RPM, and ±2 A continuous phase current drives the larger NEMA 23 motors needed for spindle-axis moves. Synchronous rectification lowers MOSFET body-diode losses, reducing thermal dissipation during continuous duty cycles. The 1/16-step microstepping smooths linear motion, important for surface finish on milled parts. Compared to the Allegro A4988, the A4983's automatic Mixed decay improves motion quality during rapid direction reversals where the A4988's fixed Slow decay can overshoot.
Recommended
Robotics Servo Motor Driver
For robotics projects requiring precise open-loop positioning of joints, the A4983SETTR-T can drive small bipolar stepper actuators directly from a 12-24 V battery or wall supply. The 1/16-step microstepping yields 3200 effective steps per revolution on a 200-step motor, providing fine angular resolution without closed-loop feedback. The 35 V VMOT rating supports battery packs up to 6S Li-ion (25.2 V) for mobile robots, with synchronous rectification keeping efficiency acceptable for battery operation. Design tip: enable Mixed decay mode for the high-acceleration direction reversals typical of joint articulation. Compared to the TI DRV8835, the A4983's higher voltage tolerance allows larger battery packs.
Recommended
Automated Textile / Sewing Machine
The A4983SETTR-T drives the feed and needle-position stepper motors in industrial sewing and embroidery machines, where precise 1/16-step positioning ensures accurate stitch placement. The ±2 A phase current supports the high-torque peak loads encountered during fabric feed, and the 35 V VMOT tolerance accommodates industrial 24 V or 30 V supply rails common in textile machinery. The automatic Mixed decay mode keeps phase current stable during rapid acceleration/deceleration cycles, reducing skipped stitches. Compared to the Allegro A4982, the A4983's 1/16-step mode enables finer stitch resolution for detailed embroidery patterns. Design tip: add a heatsink or copper pour if running continuously at >1.5 A.
Recommended
Laboratory Automation Pipette / Syringe Pump
The A4983SETTR-T drives the syringe-pump or pipette stepper in automated liquid-handling systems, where precise microstepping directly translates to dispensing volume accuracy. The 1/16-step resolution provides 3200 steps per revolution, and at a typical lead-screw of 1 mm/rev with 16 microsteps, the system delivers sub-micron positioning resolution. The 35 V rating accommodates 24 V supplies standard in lab equipment, and synchronous rectification reduces heat in continuous-precision applications. Compared to the TI DRV8835, the A4983's higher voltage tolerance enables use with 24 V supplies common in industrial lab gear. Design tip: use Slow decay mode for the very low currents typical of fine dispensing to avoid audible noise.
Recommended
Camera Slider / Pan-Tilt Head
The A4983SETTR-T is an excellent fit for motorized camera sliders and pan-tilt heads in photography rigs, where smooth 1/16-step motion is critical for cinematic video. The ±2 A continuous phase current drives mid-size NEMA 17 slider motors easily, while the 35 V VMOT tolerance supports 12 V Li-ion packs for portable rigs. Synchronous rectification keeps thermal dissipation low during long, continuous slider passes where battery life matters. Compared to the TI DRV8835, the A4983's higher voltage tolerance allows use with 3S-4S Li-ion packs for portable shooting. Design tip: pair with an MSP430 low-power MCU to keep idle current draw minimal between shots.
Recommended
Desktop Laser Engraver
The A4983SETTR-T drives the X/Y gantry steppers in desktop laser engravers, where 1/16-step microstepping directly impacts engraving resolution and smoothness of curved cuts. The ±2 A phase current handles the rapid acceleration profiles of gantry systems, and the 35 V VMOT tolerance accommodates 24 V supplies common in laser engraver enclosures. The automatic Mixed/Slow decay selection optimizes torque ripple at low speeds, important for engraving fine detail. Compared to the A4988, the A4983's automatic Mixed decay mode reduces audible mid-frequency noise during high-speed vector cuts. Design tip: add 100 µF bulk VMOT capacitance to handle motor back-EMF during rapid direction reversals.
Recommended
Recommended Products Summary
Engineering reference data for A4983SETTR-T — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | A4982SETTR-T | A4988SETTR-T | A4983SET-T | A4984SETTR-T | DRV8835DRCTR |
|---|---|---|---|---|---|---|
| Brand | Allegro MicroSystems | Allegro MicroSystems | Allegro MicroSystems | Allegro MicroSystems | Allegro MicroSystems | Texas Instruments |
| Package | QFN-28 (5x5) with EP | QFN-28 (5x5) with EP - same | QFN-28 (5x5) with EP - same | QFN-28 (5x5) with EP - same | QFN-28 (5x5) with EP - same | QFN-28 (5x5) - same |
| Motor Supply (VMOT) Max | 35 V | 35 V | 35 V | 35 V | 35 V | 11 V |
| Continuous Phase Current | ±2 A | ±2 A | ±2 A | ±2 A | ±2.5 A | 1.5 A |
| Microstep Resolution | Full, 1/2, 1/4, 1/8, 1/16 | Full, 1/2, 1/4, 1/8 (no 1/16) | Full, 1/2, 1/4, 1/8, 1/16 | Full, 1/2, 1/4, 1/8, 1/16 (same) | Full, 1/2, 1/4, 1/8, 1/16 | Up to 1/32 step |
| Current Decay Mode | Automatic Mixed / Slow | Mixed / Slow (manual) | Fixed Slow decay only | Automatic Mixed / Slow (same) | Automatic Mixed / Slow | Slow decay / fast decay (indexer controlled) |
| Synchronous Rectification | Yes | Yes | Yes | Yes (same) | Yes | Yes (PWM controlled) |
| Built-in Translator | Yes (STEP/DIR) | Yes (STEP/DIR) | Yes (STEP/DIR) | Yes (STEP/DIR) (same) | Yes (STEP/DIR) | Yes (STEP/DIR + PHASE/ENABLE) |
| Overcurrent Protection | No | No | Yes (internal OCP) | No (same) | Yes | Yes |
Key Differentiators
- Automatic Mixed/Slow decay selection (vs A4988SETTR-T)
- 1/16-step microstepping (vs A4982SETTR-T)
- 35 V VMOT rating (vs DRV8835DRCTR)
Design Notes
The QFN-28 (5x5) exposed thermal pad MUST be soldered to a copper pour of at least 1 square inch (645 mm²) to extract the heat generated by the DMOS output stage. At ±2 A continuous phase current into a 24 V VMOT supply, total package dissipation may reach 2-3 W. Without a sufficient thermal pad, the A4983SETTR-T will thermally limit at currents well below the ±2 A spec. Estimated: with 1 sq-inch 2 oz copper pour, θJA is approximately 30 °C/W; with minimal copper, θJA rises above 60 °C/W.
Place a 100 nF ceramic decoupling capacitor as close as possible to the VDD pin (logic supply) and a 10 µF + 100 nF combination near the VMOT pin. The 100 nF high-frequency decoupling must be within 2-3 mm of the IC pins to suppress switching transients. Trace the VMOT supply through a ferrite bead if the system is exposed to high-frequency noise from a switching pre-regulator. The charge-pump flying capacitor (CP1-CP2) and reservoir capacitor (CAPPV) must be ceramic, with the reservoir at least 1 µF.
Do not operate the A4983SETTR-T without the exposed thermal pad soldered — the part will overheat at moderate loads. Verify the sense resistor R_SENSE is sized correctly: ITRIP_PEAK = VREF / (8 × R_SENSE). Use a 1% or better tolerance resistor. Do not exceed the absolute maximum VMOT of 35 V; transient over-voltage spikes from motor back-EMF can exceed this — add a TVS clamp or sufficient bulk capacitance. When operating at high step rates, mixed decay mode is generally preferred to slow decay to prevent current distortion.
Route the high-current motor traces (1A, 1B, 2A, 2B, VMOT) on a separate layer with wide traces (at least 0.5 mm per ampere). Keep the SENSE1 and SENSE2 traces short, in parallel, and away from switching nodes to minimize noise pickup that could trip the current comparator prematurely. The thermal pad should connect to the GND plane with multiple thermal vias (8-12 vias, 0.3 mm diameter) for optimal heat dissipation. Source: Allegro A4983 datasheet recommended layout.
Compliance Information
RoHS compliant per Allegro product page. Not AEC-Q100 qualified (consumer/industrial grade, not automotive). Lead-free (Pb-free) per Allegro MSL marking.
