MC3479PG - Bipolar Stepper Motor Driver, 16-PDIP | onsemi
N.º da peça: MC3479PG ⚠ Última compra| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $4.2 | $4,20 |
| 10 | $3.78 | $37,80 |
| 100 | $3.3 | $330,00 |
| 500 | $2.85 | $1.425,00 |
| 1.000 | $2.5 | $2.500,00 |
MC3479PG Visão geral
A bipolar stepper motor driver is an integrated circuit that converts logic-level step and direction signals into the high-current, sequenced phase outputs required to commutate a two-phase permanent-magnet or hybrid stepper motor. In the broader system hierarchy, the MC3479PG sits inside the motor driver category, itself a subcategory of power management and motion control ICs that bridge low-power microcontrollers and high-power electromechanical actuators. The MC3479PG was widely adopted in early floppy-disk head positioners, printers, plotters, and small CNC machines of the late 1980s and 1990s.
Key features of the MC3479PG include CMOS-compatible inputs, internal logic that performs full- and half-step sequencing, integrated clamp diodes for inductive flyback, and a Phase A state indicator output that lets the host processor sense rotor position for closed-loop control. The device operates from a motor supply up to 7.2V and a logic supply of 5V, with each phase capable of sourcing or sinking 350mA continuously. Its built-in decoding eliminates the host-side state-machine burden typically required when driving stepper coils with discrete transistors.
The architecture combines four Schmitt-trigger input buffers, a sequencing decoder, two push-pull driver outputs, and flyback protection on every phase node. The full-step duplex sequence (Mode 1) advances both phase currents simultaneously, while half-step operation (Mode 2) alternates single-phase and dual-phase excitation to double mechanical resolution. This on-chip sequencing explains why the MC3479PG remained popular long after its introduction - it removes the need for external firmware state tables.
Typical applications include floppy-disk head positioners, dot-matrix and inkjet printer carriage drives, small X-Y plotters, robotics hobby drives, and any embedded motion subsystem that needs an inexpensive, self-contained two-phase stepper controller. The 350mA continuous rating makes it ideal for NEMA-size 11 and small NEMA 17 motors in the 5V to 6V coil range.
When designing with this part, place 0.1uF ceramic bypass capacitors on both the motor supply and the 5V logic supply, keep the PCB traces from each output to its motor coil short and matched, and confirm that the load current does not exceed 350mA per phase. Although the MC3479PG has been declared Last Time Buy by onsemi, it remains broadly available through distribution for legacy repair and industrial maintenance.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, including a parametric cross-reference against modern bipolar stepper drivers for engineers maintaining legacy motion systems.
Alternativas drop-in para MC3479PG — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
MC3479P
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
MC3479PG Classificações máximas e características elétricas
| Motor Type | Two-phase bipolar stepper |
| Operating Mode | Full-step duplex or half-step (mode-selectable) |
| Motor Supply Voltage (V_M) | 7.2 V maximum |
| Logic Supply Voltage (V_CC) | 5 V typical |
| Continuous Phase Output Current | 350 mA per phase |
| Input Type | CMOS-compatible Schmitt trigger |
| Number of Input Pins | 4 (Phase A, Phase B, Mode, Direction / Clock equivalents) |
| On-chip Sequencing | Yes (logic decoding/sequencing section) |
| Driver Stages | 2 (one per motor coil) |
| Phase A State Indicator Output | Yes |
| Integrated Clamp Diodes | Yes (for inductive flyback) |
| Encapsulamento | 16-pin PDIP (through-hole) |
| Tipo de montagem | Through-hole |
| Status RoHS | Compliant |
| Manufacturer | onsemi (formerly ON Semiconductor / Motorola Semiconductor) |
| Topologia | Bipolar, push-pull driver outputs |
Configuração de pinos do MC3479PG
| Pino 1 | Phase A Input / CLOCK — Step clock input for Phase A sequencing (CMOS Schmitt trigger) |
| Pino 2 | Phase B Input / DIRECTION — Direction control input for Phase B sequencing (CMOS Schmitt trigger) |
| Pino 3 | MODE — Full-step / half-step mode select input |
| Pino 4 | I4 / ENABLE — Logic input for enable / sequencing control |
| Pino 5 | V_CC — 5V logic supply |
| Pino 6 | V_M — Motor supply voltage (up to 7.2 V) |
| Pino 7 | OUT A — Phase A driver output to motor coil |
| Pino 8 | OUT A — Phase A driver output (return to motor coil) |
| Pino 9 | GND — Ground |
| Pino 10 | OUT B — Phase B driver output to motor coil |
| Pino 11 | OUT B — Phase B driver output (return to motor coil) |
| Pino 12 | PHASE A OUT — Phase A state indicator output (logic level) |
| Pino 13 | NC — Not connected (per datasheet) |
| Pino 14 | NC — Not connected (per datasheet) |
| Pino 15 | NC — Not connected (per datasheet) |
| Pino 16 | NC — Not connected (per datasheet) |
Aplicações típicas
MC3479PG é adequado para 6 aplicaçãos: Floppy-Disk Head Positioner, Dot-Matrix and Inkjet Printer Carriage, Small X-Y Plotter and Pen Plotter, Robotics Hobbyist Stepper Driver, Industrial Maintenance / Legacy Repair, Vintage Computer Restoration.
Floppy-Disk Head Positioner
The MC3479PG's on-chip sequencing and 350mA per-phase drive make it a textbook choice for legacy 3.5-inch and 5.25-inch floppy-disk head positioners that use small bipolar stepper motors with 5V coils. Its CMOS-compatible inputs interface cleanly to the floppy controller logic, and the integrated Phase A indicator output lets the host sense rotor position for seek verification. Compared with discrete transistor bridges, the MC3479PG eliminates a state-machine firmware table and saves roughly 12 to 16 components per drive. The 16-PDIP package was convenient for early 1980s through-hole PCB assemblies used in IBM PC/AT-class machines, and most floppy subsystems of that era specified this exact part.
Recomendado
Dot-Matrix and Inkjet Printer Carriage
Dot-matrix line-feed motors and inkjet carriage-drive steppers historically used the MC3479PG because its bipolar mode and built-in sequencing simplified the carriage-control firmware. The 350mA continuous rating comfortably drives small NEMA-size 11 carriage motors in 5V-coil printer mechanisms, and the half-step mode doubles mechanical resolution to 400 steps per revolution from a typical 200-step motor, smoothing print artifacts. The device's Phase A output also enables the printer controller to perform a homing sequence by counting steps until the indicator asserts.
Recomendado
Small X-Y Plotter and Pen Plotter
Small X-Y plotters and pen plotters of the late 1980s and early 1990s relied on the MC3479PG to drive the X and Y axis bipolar stepper motors because the on-chip sequencing and Phase A indicator simplified the host-firmware stepper-control loop. Each axis uses one MC3479PG, and the full-step duplex or half-step mode is selectable per axis. The 7.2V motor supply matches the 6V coil rating of common plotter stepper motors, eliminating the need for a higher-voltage rail. Because the MC3479PG requires only 5V logic and 7.2V motor supplies, it fits cleanly into USB-powered plotter designs.
Recomendado
Robotics Hobbyist Stepper Driver
Hobby robotics projects of the 1990s and early 2000s used the MC3479PG as a low-cost, easy-to-integrate bipolar stepper driver because it required no external sequencing firmware and exposed CMOS-compatible logic inputs to microcontrollers such as the BASIC Stamp and early PIC microcontrollers. With 350mA per-phase, it drives small NEMA 11 and NEMA 14 stepper motors used in pan-tilt mechanisms, small wheeled-robot drivetrains, and educational robotic arms. The Phase A indicator output also enables closed-loop position verification in simple encoder-less designs. Today, the part is still used in legacy repair and educational kits.
Recomendado
Industrial Maintenance / Legacy Repair
The MC3479PG is in widespread use as a maintenance replacement part for legacy CNC retrofit kits, embroidery-machine head positioners, and industrial labeling machines whose original designs specified the part in the late 1980s. Because the MC3479PG is in Last Time Buy, the remaining onsemi and Motorola-stock inventory is the principal supply for technicians performing repairs on equipment with 20- to 30-year service life. The Phase A indicator output also aids troubleshooting because technicians can probe it with an oscilloscope to verify the sequencing logic is operational before suspecting the motor itself.
Recomendado
Vintage Computer Restoration
Restorers of vintage IBM PC/AT, Apple Macintosh, and Commodore Amiga floppy drives rely on the MC3479PG as the original-equipment stepper driver in many of those disk subsystems, and the part is in active demand on the vintage-repair market. Its 16-PDIP through-hole package matches the original through-hole PCB designs of the era and avoids the need for adapter boards. The 5V logic and 7.2V motor supply rails are also identical to the floppy-drive subsystem rails, simplifying the restoration to original specification.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para MC3479PG — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | MC3479P | MC3479G |
|---|---|---|---|
| Package | 16-PDIP | 16-PDIP (same) | 16-SOIC wide (different footprint) |
| Brand | onsemi | onsemi | onsemi |
| Motor Type | Bipolar two-phase stepper | Bipolar two-phase stepper | Bipolar two-phase stepper |
| Maximum Motor Supply | 7.2 V | 7.2 V | 7.2 V |
| Continuous Phase Current | 350 mA | 350 mA | 350 mA |
| On-chip Sequencing | Yes (full / half step) | Yes (full / half step) | Yes (full / half step) |
| Phase A Indicator Output | Yes | Yes | Yes |
| Lifecycle Status | Last Time Buy | Last Time Buy (older SnPb finish) | Last Time Buy |
| RoHS / Lead-Free | Yes (PG suffix) | No (SnPb finish) | Yes (G suffix) |
Principais diferenciais
- On-chip full-step and half-step sequencing eliminates external state-machine firmware (vs L293D)
- Phase A indicator output enables closed-loop position sensing without an external encoder (vs DRV8833)
- Single 16-PDIP through-hole package matches vintage 1980s/1990s PCBs (vs L6207PD (PowerSO-36))
Notas de projeto
The MC3479PG requires two supplies: V_CC at 5V for the CMOS logic and V_M up to 7.2V for the motor coils. Place a 0.1uF ceramic bypass capacitor directly on the V_CC pin and a 10uF electrolytic + 0.1uF ceramic on V_M to suppress the back-EMF spikes from the motor coils. The internal clamp diodes handle most inductive flyback, but the bulk capacitor prevents supply-rail collapse during full-step commutation at high step rates.
Estimated: at 7.2V motor supply, 350mA continuous per phase, full-step duplex mode, the worst-case power dissipation in each driver stage is approximately (7.2V - V_coil) x 350mA. For a 5V coil motor, this is ~0.77W per phase and ~1.5W total - within the 16-PDIP package's 90 C/W theta_JA thermal envelope at 25C ambient. If both phases are saturated simultaneously in full-step duplex, derate by 20% above 60C ambient or add a small clip-on heatsink.
Keep the PCB traces from OUT A and OUT B to the motor coils short and matched in length to minimize impedance imbalance and radiated EMI. Use a ground plane on the underside of the PCB and route the motor traces on the top side away from sensitive analog or logic lines. Place the 0.1uF V_M bypass capacitor within 5mm of the V_M pin, and keep the logic input traces short to avoid picking up motor-coil noise into the CMOS Schmitt triggers.
Do not exceed 7.2V on the V_M pin - the device has no over-voltage protection and motor-coil back-EMF at high step rates can push the rail above the absolute maximum. Do not parallel the OUT A and OUT B pins to double the current; use one MC3479PG per motor. Do not drive the CMOS inputs with 12V or 15V logic - the inputs are rated to V_CC plus 0.3V maximum and require level shifting if a 12V microcontroller is used.
Informações de conformidade
PG suffix indicates lead-free / RoHS-compliant finish; the older P suffix was SnPb finish and is not RoHS-compliant. Halogen-free status not explicitly stated in the onsemi datasheet; conflict-minerals compliance per onsemi corporate policy.
