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Allegro MicroSystems A3966ELBTR-T
- Part No.:
- A3966ELBTR-T
- Manufacturer:
- Allegro MicroSystems
- Category:
- Motor Drivers, Controllers
- Package:
- 16-PowerSOIC (0.295", 7.50mm Width)
- Datasheet:
-
A3966ELBTR-T.pdf
- Description:
- IC MTRDRV BIPLR 4.75-5.5V 16SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,645
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Product details
Overview
A3966ELBTR-T from Allegro MicroSystems is a dual full-bridge PWM motor driver IC designed to control both windings of a bipolar stepper motor. It delivers ±650 mA continuous output current per bridge, supports up to 30 V load supply voltage, and integrates fixed-frequency PWM current regulation with user-selectable blanking via external RC network. It is used in precision motion control systems such as industrial automation actuators and medical fluid pumps.
For engineers reviewing the A3966ELBTR-T datasheet, A3966ELBTR-T pinout, A3966ELBTR-T application, or A3966ELBTR-T equivalent, key selection criteria include its Satlington® sink-driver architecture, internal thermal shutdown with 15 °C hysteresis, ±750 mA peak current capability, and SOICW-16 package with fused ground pins for enhanced thermal dissipation.
Technical Context
The A3966ELBTR-T implements two independent full-bridge drivers with source/sink control logic governed by PHASE and ENABLE inputs. Each bridge uses a fixed-frequency oscillator (22.9–27.9 kHz with 56 kΩ/680 pF) to drive PWM latches that regulate winding current via external sense resistors and a 4×-divided reference voltage.
Current regulation relies on a comparator blanking window (1.3 µs nominal) synchronized to source turn-on and PHASE/ENABLE transitions, preventing false triggering from diode reverse-recovery spikes. Crossover-current protection enforces ~1 µs dead time between source/sink switching, and UVLO disables outputs below 4.1 V logic supply.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Continuous Output Current | ±650 mA per bridge - sufficient for NEMA 11–14 stepper motors at 24 V with moderate torque requirements |
| Peak Output Current | ±750 mA - enables short-duration acceleration bursts without thermal derating |
| Load Supply Voltage | 30 V max - compatible with standard industrial 24 V rails including transient margin |
| PWM Oscillator Frequency | 25.4 kHz typical (56 kΩ + 680 pF) - balances ripple reduction against switching loss and EMI |
| Saturation Voltage (Sink) | 0.7 V at +650 mA - low conduction loss enabled by Satlington® structure |
| Thermal Shutdown Threshold | 165 °C typical with 15 °C hysteresis - prevents latch-up during sustained overload or poor heatsinking |
| Logic Supply Range | 4.75–5.5 V - matches standard 5 V microcontroller I/O without level-shifting |
Pinout & Package
Package: 16-pin SOICW (suffix LB), with pins 4 and 13 internally fused to the die pad for improved thermal performance. The package is lead-free with 100% matte tin plating and rated for –20 °C to +85 °C ambient operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| OUT1A, OUT1B, OUT2A, OUT2B | Full-bridge output terminals | Drive motor winding ends; each pair forms one H-bridge with bidirectional current capability |
| PHASE1, PHASE2 | Polarity control input | Determines current direction per bridge (H/L sets OUTA→OUTB or OUTB→OUTA flow) |
| ENABLE1, ENABLE2 | Bridge enable/disable input | High = all outputs off; low = active PWM control; supports external PWM for fast decay |
| VBB | Motor supply input | Connects to 30 V max load rail; requires local 47 µF decoupling capacitor |
| VCC | Logic supply input | 5 V digital supply; powers internal logic, comparators, and oscillators |
| SENSE1, SENSE2 | Current-sense input | Accepts voltage drop across external sense resistor (RS); referenced to ground |
| VREF | Reference voltage input | 0–2 V input divided by 4 internally to set current trip threshold (ITRIP = VREF/(4 × RS) + 18 mA) |
| RC | Oscillator timing node | Connects external RT–CT network; CT also sets blanking window (tblank = 1900 × CT) |
| GROUND | Power and signal ground | Pins 2, 3, 14, 15, and die pad (pins 4 & 13) are internally connected to GND |
Key Features
| Feature | Design Value |
|---|---|
| Satlington® sink drivers | Combines Darlington-level peak current (±750 mA) with saturated-transistor-level VCE(SAT) (0.7 V @ 650 mA), reducing conduction loss and heat generation |
| User-selectable blanking window | Programmable via CT capacitor (tblank = 1900 × CT); eliminates false current-limit triggering during switching transients |
| Integrated ground-clamp and flyback diodes | Eliminates need for external freewheeling diodes; enables fast current decay paths during PWM off-time |
| Crossover-current protection | ~1 µs internal dead time between source/sink switching prevents shoot-through and device failure under dynamic phase reversal |
| Thermal shutdown with hysteresis | Shuts down at 165 °C junction temperature and re-enables only after cooling by ≥15 °C - avoids thermal oscillation during marginal conditions |
Applications
| Industrial CNC Positioning Stage | Medical Infusion Pump Actuator |
|---|---|
Use Scenario: Precise open-loop positioning of XY gantry stages using 1.8° bipolar stepper motors. IC Role / Device Role / Timing Role: Dual full-bridge driver executing microstepping-compatible PHASE/ENABLE sequencing with stable current regulation. Use Value: ±650 mA drive ensures holding torque >0.3 N·m at 24 V; integrated blanking prevents step loss during rapid direction changes. | Use Scenario: Controlled syringe advancement in battery-powered portable infusion devices. IC Role / Device Role / Timing Role: Low-noise, thermally robust motor driver enabling silent, repeatable peristaltic motion with minimal PCB area. Use Value: Satlington® sink drivers reduce power dissipation vs. standard H-bridges, extending battery life; SOICW package allows direct heatsinking to metal enclosure. |
| Automated Laboratory Sample Handler | 3D Printer Extruder Stepper Control |
Use Scenario: Multi-axis robotic arm handling vials and plates in ISO-classified environments. IC Role / Device Role / Timing Role: Bipolar stepper driver with ENABLE-based PWM decay control for smooth, vibration-minimized motion profiles. Use Value: Internal UVLO and thermal shutdown ensure fail-safe motor stop during brownout or jam; 30 V rating accommodates 24 V system with surge margin. | Use Scenario: Compact extruder motor control requiring high reliability and minimal external components. IC Role / Device Role / Timing Role: Integrated dual-H-bridge with fixed-frequency PWM current control eliminating need for external current-sense amplifiers or gate drivers. Use Value: RC-timed oscillator (25 kHz) reduces audible noise vs. lower-frequency alternatives while maintaining low MOSFET switching loss. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual full-bridge motor driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TB6600HG | Higher 4 A peak current, external MOSFET drivers, no integrated current sensing or blanking | Requires external current-sense amplifier, gate drivers, and protection circuitry; suited for high-power (>1 A) steppers | Select when scaling beyond ±650 mA or needing programmable decay modes; not drop-in due to different control interface and layout |
| DRV8825 | Microstepping support, integrated indexer, 1.5 A max, 3.3/5 V logic compatible, no Satlington® architecture | Targets compact, low-cost printer/maker applications; lacks blanking window and thermal hysteresis spec | Prefer for systems requiring onboard microstepping or space-constrained designs; verify thermal performance at 650 mA continuous |
Compared with TB6600HG and DRV8825, the A3966ELBTR-T offers unique Satlington® sink efficiency and factory-trimmed blanking timing-critical for stable current regulation in industrial-grade stepper systems where external component count and thermal margin are design constraints.
Availability
A3966ELBTR-T is available at Aetrix Electronics and suitable for industrial CNC positioning stages, medical infusion pump actuators, automated laboratory sample handlers, and 3D printer extruder stepper control requiring stable component supply and long-term lifecycle assurance.
Supply support for A3966ELBTR-T 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
Allegro MicroSystems is a U.S.-based designer and manufacturer of high-performance magnetic sensors and power ICs, founded in 1989 and headquartered in Manchester, NH.
The A3966ELBTR-T belongs to Allegro's precision motor driver product line, engineered specifically for reliable, thermally efficient bipolar stepper control in industrial and medical equipment where integration, protection, and current accuracy are critical.
FAQ
What is the maximum continuous output current per bridge of the A3966ELBTR-T?
The A3966ELBTR-T supports ±650 mA continuous output current per full-bridge under specified thermal conditions (TA ≤ 85 °C, adequate PCB copper). This rating assumes use of the SOICW-16 package with pins 4 and 13 connected to ground plane for thermal enhancement. Peak current reaches ±750 mA for short durations before thermal limiting engages.
How does the A3966ELBTR-T implement current regulation without an external controller?
The A3966ELBTR-T uses an internal fixed-frequency PWM current-control circuit that compares voltage across an external sense resistor (RS) to a trip threshold derived from VREF/4. When current reaches ITRIP = VREF/(4 × RS) + 18 mA, the source driver turns off; current recirculates through the sink driver and internal clamp diodes until the oscillator resets the latch. This fully autonomous regulation requires no MCU intervention.
What is the purpose of the RC pin on the A3966ELBTR-T, and how is it configured?
The RC pin on the A3966ELBTR-T connects to an external resistor (RT) and capacitor (CT) that jointly set both the internal oscillator frequency (fosc ≈ 1/(RT × CT)) and the current-sense comparator blanking window (tblank = 1900 × CT). With nominal 56 kΩ and 680 pF, fosc = 25.4 kHz and tblank = 1.3 µs - values optimized to suppress switching transients while maintaining regulation stability.
Does the A3966ELBTR-T require external flyback diodes for stepper motor operation?
No, the A3966ELBTR-T integrates ground-clamp and flyback diodes within each full-bridge. These diodes provide recirculation paths during PWM off-time and enable fast current decay without external components. This integration reduces BOM count, PCB area, and layout complexity while ensuring matched diode characteristics across both bridges.
What thermal protection features are built into the A3966ELBTR-T?
The A3966ELBTR-T includes internal thermal shutdown that disables all outputs when junction temperature reaches 165 °C typical, with 15 °C hysteresis to prevent oscillation. It also incorporates UVLO protection that disables drivers if VCC drops below 4.1 V, and crossover-current protection enforcing ~1 µs dead time between source/sink switching - collectively safeguarding against overtemperature, undervoltage, and shoot-through faults.
A3966ELBTR-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Allegro MicroSystems
- Series:
- -
- Package/Case:
- 16-PowerSOIC (0.295", 7.50mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Motor Type - Stepper:
- Bipolar
- Motor Type - AC, DC:
- -
- Function:
- Driver - Fully Integrated, Control and Power Stage
- Output Configuration:
- Half Bridge (4)
- Interface:
- Parallel
- Technology:
- Bipolar
- Step Resolution:
- -
- Applications:
- General Purpose
- Current - Output:
- 650mA
- Voltage - Supply:
- 4.75V ~ 5.5V
- Voltage - Load:
- 4.75V ~ 30V
- Operating Temperature:
- -20°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SOIC
A3966ELBTR-T FAQ
1.How can I place an order for A3966ELBTR-T through Aetrix?
Please submit a Request for Quotation (RFQ) for A3966ELBTR-T on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for A3966ELBTR-T reliable?
The price and inventory of A3966ELBTR-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for A3966ELBTR-T is usually 5 days.
3.What payment methods are accepted for A3966ELBTR-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for A3966ELBTR-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for A3966ELBTR-T?
A3966ELBTR-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your A3966ELBTR-T order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for A3966ELBTR-T?
For technical support, including A3966ELBTR-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your A3966ELBTR-T requirements.
6.How does Aetrix verify that A3966ELBTR-T is sourced from the original manufacturer or authorized distributors?
All A3966ELBTR-T products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that A3966ELBTR-T meets industry standards.
7.What is the process for return or replacement of A3966ELBTR-T?
All A3966ELBTR-T units undergo pre-shipment inspection (PSI). If there is an issue with A3966ELBTR-T, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The A3966ELBTR-T part is unused and in its original packaging.
Return procedure for A3966ELBTR-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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