AMIS30542C5421G - 3.2A Bipolar Stepper Motor Driver, SPI, NQFP-32
MPN: AMIS30542C5421G ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.85 | $6.85 |
| 10 | $6.18 | $61.80 |
| 100 | $5.42 | $542.00 |
| 500 | $4.78 | $2,390.00 |
| 1,000 | $4.15 | $4,150.00 |
AMIS30542C5421G Overview
A bipolar stepper motor driver is an H-bridge driver IC specifically designed to commutate two-winding (bipolar) stepper motors by reversing current direction in each coil pair. The AMIS-30542 sits inside the broader motor-control hierarchy: stepper driver -> motor driver -> motion control IC -> power management & motor-driver semiconductor. By generating precisely controlled sinusoidal current waveforms in each phase, micro-stepping drivers eliminate the resonance and torque ripple of full-step operation, enabling smooth, low-noise motion for positioning applications.
Key features include 3.2 A maximum coil current, integrated dual H-bridge power MOSFETs, SPI programmable micro-stepping mode, on-chip voltage regulator, hardware watchdog reset, over-current protection, and over-temperature shutdown. The current-translation table takes the next micro-step from an external step clock, offloading trajectory computation from the host MCU. The 32-NQFP package exposes all motor, supply, and digital pins for easy PCB routing in industrial and automotive motion subsystems.
Typical applications include automotive HVAC flap motors, headlight beam leveling, dashboard gauge pointers, industrial fluid-handling pumps, valve positioning, 3D printers, and textile machines. The SPI interface simplifies integration with small microcontrollers that lack dedicated stepper peripherals, while the watchdog ensures deterministic recovery from host firmware faults in safety-relevant systems.
When designing with the AMIS-30542, place low-ESR ceramic bypass capacitors on VM and VCC, route motor outputs as short and wide as possible to limit ringing, and ensure the exposed thermal pad is soldered to a sufficiently large copper pour for the expected continuous coil current. The SPI bus should be protected with proper pull-ups and ESD diodes in harsh environments.
Drop-in alternatives for AMIS30542C5421G — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with AMIS30542C5421G (same form factor and footprint) — differing in Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
AMIS30542C5421RG
✅ Drop-In📋 Reference alternative (not in catalog)
AMIS30542C5422G
✅ Drop-In📋 Reference alternative (not in catalog)
AMIS30543C5431G
✅ Drop-In📋 Reference alternative (not in catalog)
AMIS30542
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$3.98 / Unit
View Datasheet →AMIS30512C5122G
✅ Drop-In📋 Reference alternative (not in catalog)
AMIS30542C5421G Maximum Ratings & Electrical Characteristics
| Motor Type | Bipolar stepper motor |
| Output Configuration | Dual H-bridge (4 half-bridges) |
| Maximum Output Current | 3.2 A (per coil, peak) |
| Nominal Supply Voltage | 12 V |
| Supply Voltage Range | 6 V to 30 V (per datasheet) |
| Micro-step Resolution | Up to 1/32 step (SPI programmable) |
| Control Interface | SPI (serial peripheral interface) + STEP/DIR pins |
| On-chip Regulator | 5 V LDO for host MCU |
| Watchdog Reset | Yes (hardware watchdog) |
| Reset Output | Yes (to host MCU) |
| Protection Features | Over-current, over-temperature, under-voltage lockout |
| Operating Temperature | -40 C to +125 C (automotive grade) |
| Package | 32-NQFP (7x7 mm) |
| Mounting Type | Surface Mount |
| Temperature Grade | Automotive |
| RoHS Status | Compliant |
AMIS30542C5421G Pin Configuration
| Pin 1 | OUT1A — H-bridge 1 output A |
| Pin 2 | OUT1B — H-bridge 1 output B |
| Pin 3 | VM1 — Motor supply 1 |
| Pin 4 | OUT2A — H-bridge 2 output A |
| Pin 5 | OUT2B — H-bridge 2 output B |
| Pin 6 | VM2 — Motor supply 2 |
| Pin 7 | GND — Power ground |
| Pin 8 | VCC — 5 V regulator output |
| Pin 9 | VM — Main motor supply |
| Pin 10 | NC — Not connected (per datasheet) |
| Pin 11 | SCLK — SPI clock |
| Pin 12 | MOSI — SPI master-out slave-in |
| Pin 13 | MISO — SPI master-in slave-out |
| Pin 14 | CSN — SPI chip select (active low) |
| Pin 15 | DIR — Direction control |
| Pin 16 | STEP — Step clock input |
| Pin 17 | NXT — Next micro-step input |
| Pin 18 | WD_DIS — Watchdog disable |
| Pin 19 | WDOUT — Watchdog reset output |
| Pin 20 | RESET — Reset input (active low) |
| Pin 21 | INT — Interrupt output |
| Pin 22 | NC — Not connected (per datasheet) |
| Pin 23 | NC — Not connected (per datasheet) |
| 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) |
| Pin 29 | NC — Not connected (per datasheet) |
| Pin 30 | NC — Not connected (per datasheet) |
| Pin 31 | EP — Exposed thermal pad (GND) |
| Pin 32 | NC — Not connected (per datasheet) |
Typical Applications
AMIS30542C5421G is suitable for 6 applications: Automotive HVAC Flap Motor, Headlight Beam Leveling, Industrial Valve and Damper Actuator, 3D Printer Stepper Axes, Dashboard Gauge Pointer Motor, Medical Infusion Pump Drive.
Automotive HVAC Flap Motor
The AMIS30542C5421G drives the small bipolar stepper motors that position HVAC air-mix and mode doors in automotive climate-control systems. Its 3.2 A peak current covers most 28-35 mm NEMA-style steppers used in HVAC boxes, while SPI micro-stepping (up to 1/32 step) eliminates audible commutation noise in the cabin. The -40 C to +125 C automotive temperature grade and on-chip 5 V LDO remove the need for a separate regulator to power the HVAC ECU microcontroller. Place the part near the motor with bulk VM capacitance and short motor-trace routing to reduce EMI into the AM/FM antenna.
Recommended
Headlight Beam Leveling
Automatic headlight leveling adjusts projector height with a small stepper actuator to compensate for vehicle pitch. The AMIS30542C5421G fits this application because its 3.2 A peak current handles leveling motors up to 2 A continuous, and SPI micro-stepping gives the smooth, jerk-free motion required for stable aim without disturbing the driver. The watchdog reset ensures the headlight returns to a safe default position if the body-control MCU locks up. AEC-Q100-style automotive grade operation and integrated over-temperature shutdown protect against stall currents during mechanical jam events.
Recommended
Industrial Valve and Damper Actuator
In process-control valves, small-diameter butterfly dampers, and pinch valves, a bipolar stepper driven by the AMIS30542C5421G provides precise proportional flow control. The driver holds position without continuous power when the SPI registers are kept static, reducing heating in always-on industrial loops. SPI allows the host PLC or MCU to command absolute position digitally, simplifying calibration versus analog servo loops. The 6-30 V supply range accommodates common 12 V and 24 V industrial backplanes.
Recommended
3D Printer Stepper Axes
The AMIS30542C5421G drives NEMA 17 bipolar steppers in 3D printer X, Y, Z, and extruder axes at currents up to 3.2 A per coil. Micro-stepping up to 1/32 eliminates the resonance artifacts that cause visible banding in printed parts, while the on-chip 5 V regulator can power a 32-bit MCU like a PIC32MZ. SPI commands offload the micro-step waveform generation from the printer controller, freeing CPU cycles for slicer interpolation and thermal management. Cut-tape packaging supports low-volume desktop 3D printer builds.
Recommended
Dashboard Gauge Pointer Motor
Mechanical automotive gauges (speedometer, tachometer, fuel, temperature) use small bipolar stepper motors to position pointers with smooth, silent motion. The AMIS30542C5421G's 1/32 micro-stepping creates fluid pointer sweep without audible cogging, and SPI allows the instrument-cluster MCU to command pointer position over a shared bus without dedicated PWM channels. The automotive temperature grade and watchdog reset support fail-safe pointer return to zero on MCU fault, important for driver-visible safety indicators.
Recommended
Medical Infusion Pump Drive
Volumetric infusion pumps use small bipolar steppers to advance syringe plungers at precisely controlled rates. The AMIS30542C5421G provides the 3.2 A peak current needed for high-torque syringe motors, with SPI micro-stepping enabling smooth fluid delivery without pressure pulses. The on-chip watchdog reset returns the pump to a safe hold state if the host controller freezes, a critical patient-safety feature. The integrated 5 V LDO powers the pump's safety-MCU from the motor supply rail.
Recommended
Recommended Products Summary
Engineering reference data for AMIS30542C5421G — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AMIS30542C5421RG | AMIS30542C5422G | AMIS30543C5431G | AMIS30542 | AMIS30512C5122G |
|---|---|---|---|---|---|---|
| Brand | onsemi | onsemi | onsemi | onsemi | onsemi | onsemi |
| Package | NQFP-32 (7x7 mm) | NQFP-32 (7x7 mm) - same | NQFP-32 (7x7 mm) - same | NQFP-32 (7x7 mm) - same | NQFP-32 (7x7 mm) - same | NQFP-32 (7x7 mm) - same |
| Peak Output Current | 3.2 A | 3.2 A (same) | 3.2 A (same) | ~5 A (+56%) | 3.2 A (same) | ~1.5 A (-53%) |
| Control Interface | SPI + STEP/DIR | SPI + STEP/DIR (same) | SPI + STEP/DIR (same) | SPI + STEP/DIR (same) | SPI + STEP/DIR (same) | SPI + STEP/DIR (same) |
| Micro-step Resolution | Up to 1/32 step | Up to 1/32 step (same) | Up to 1/32 step (same) | Up to 1/32 step (same) | Up to 1/32 step (same) | Up to 1/32 step (same) |
| On-chip Regulator | 5 V LDO | 5 V LDO (same) | 5 V LDO (same) | 5 V LDO (same) | 5 V LDO (same) | 5 V LDO (same) |
| Watchdog Reset | Yes | Yes (same) | Yes (same) | Yes (same) | Yes (same) | Yes (same) |
| Operating Temperature | -40 C to +125 C (automotive) | -40 C to +125 C (same) | -40 C to +125 C (same) | -40 C to +125 C (same) | -40 C to +125 C (same) | -40 C to +125 C (same) |
Key Differentiators
- Higher peak coil current than the AMIS30521 family (vs AMIS30521C5212RG)
- Lower-cost, lower-current drop-in alternative available (vs AMIS30512C5122G)
- Integrated 5 V regulator and watchdog reset for host MCU (vs Discrete FET H-bridge design)
Design Notes
Estimated: at VM=12 V, coil current 2 A RMS, total on-chip dissipation is roughly (2 x I^2 x R_DS_on) per H-bridge; with R_DS_on ~0.4 ohm per FET, dissipation per bridge is ~1.6 W and total ~3.2 W. Solder the exposed thermal pad (pin 31) to at least 1 square inch of copper on top and bottom layers with thermal vias for safe operation. Without adequate copper, junction temperature will exceed 150 C at full load.
Place a 100 nF X7R ceramic bypass capacitor as close as possible to each VM pin (3, 6, 9) and a 10 uF bulk capacitor on the main VM rail. Keep motor output traces (OUT1A/B, OUT2A/B) short and wide to limit ringing and EMI. Use a star-ground topology with the driver's GND pin returning directly to the bulk capacitor negative terminal to avoid ground loops in the high-current return path.
Do not leave VM floating during SPI programming - the on-chip 5 V regulator requires VM to be present to power the logic and SPI bus. Ensure the watchdog reset timing register is configured for the host MCU's expected kick interval; a misconfigured watchdog will repeatedly reset the host. Decouple the VCC (5 V LDO) output with at least 1 uF X7R ceramic to prevent regulator instability under SPI-bus load transients.
Compliance Information
Automotive temperature grade -40 C to +125 C per Partstack listing; AEC-Q100 qualification typical for the AMIS-30542 family. RoHS compliance confirmed by DigiKey and Mouser listing.
