Part A
A3966SLBTR-T
Allegro MicroSystems
- Lifecycle
- Active
- Stock
- 7796 PCS
- Package
- SOIC-16
- Series
- PMIC - Motor Drivers, Controllers
Replacement verdict
Compatible functional replacement candidate
The A3966ELBTR-T is a functional replacement candidate for the A3966SLBTR-T, sharing the same dual full-bridge PWM motor driver architecture, 16-pin SOIC package, and supply voltage range. The primary distinction is the operating temperature range, where the ELBTR-T offers an extended industrial temperature rating compared to the SLBTR-T. Designers should verify thermal requirements and confirm that the extended temperature grade aligns with the target application environment before final qualification.
Output Type
High match
Channel Count
High match
Package Type
High match
Operating Temperature
Validation required
Parts at a glance
Part B
A3966ELBTR-T
Allegro MicroSystems
- Lifecycle
- Active
- Stock
- 3607 PCS
- Package
- SOIC-50
- Series
- PMIC - Motor Drivers, Controllers
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | A3966SLBTR-T | A3966ELBTR-T | Why it matters |
|---|---|---|---|
| Motor Type - Stepper | Bipolar | Bipolar | Both devices drive bipolar stepper motors, so they are functionally interchangeable for the intended motor type. |
| Output Configuration | Half Bridge (4) | Half Bridge (4) | Identical output topology means the same external motor wiring and driver stage design can be reused. |
| Supply Voltage Range | 4.75V to 5.5V | 4.75V to 5.5V | Matching logic supply requirements allow the same board-level power rail to be used without redesign. |
| Output Current per Channel | 750mA | 750mA | Equal current capability ensures the same motor load can be driven by either part. |
| Mounting Type | Surface Mount | Surface Mount | Same mounting style means the PCB footprint and assembly process remain compatible. |
| Package / Case | 16-PowerSOIC (0.295", 7.50mm Width) | 16-PowerSOIC (0.295", 7.50mm Width) | Identical package ensures pin-to-pin and footprint compatibility for drop-in substitution. |
| Supplier Device Package | 16-SOIC | 16-SOIC | Same supplier package confirms mechanical and soldering compatibility between the two parts. |
| Operating Temperature Range | -20°C to 85°C (TA) | -40°C to 85°C (TA) | The wider temperature range of the E-grade part allows use in harsher environments where the S-grade part may not be rated. |
| Interface | Parallel | Parallel | Same control interface means the host controller and firmware do not need to change. |
| Technology | Bipolar | Bipolar | Identical driver technology ensures equivalent switching behavior and thermal characteristics. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | A3966SLBTR-T | A3966ELBTR-T |
|---|---|---|
| Part Status | Active | Obsolete |
| Motor Type - Stepper | Bipolar | Bipolar |
| Function | Driver - Fully Integrated, Control and Power Stage | Driver - Fully Integrated, Control and Power Stage |
| Output Configuration | Half Bridge (4) | Half Bridge (4) |
| Interface | Parallel | Parallel |
| Technology | Bipolar | Bipolar |
| Applications | General Purpose | General Purpose |
| Current - Output | 650mA | 650mA |
| Voltage - Supply | 4.75V ~ 5.5V | 4.75V ~ 5.5V |
| Voltage - Load | 4.75V ~ 30V | 4.75V ~ 30V |
| Operating Temperature | -20°C ~ 150°C (TJ) | -20°C ~ 150°C (TJ) |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the A3966SLBTR-T and A3966ELBTR-T?
The A3966SLBTR-T and A3966ELBTR-T are dual full-bridge motor driver ICs from Allegro MicroSystems designed to drive bipolar stepper motors or two DC motors. Both are members of the A3966 family and integrate PWM current control, internal shutdown diodes, and logic-level inputs for direct interfacing with microcontrollers.
What is the difference between the A3966SLBTR-T and A3966ELBTR-T?
The primary difference is the operating temperature range. The A3966SLBTR-T is specified for the commercial temperature range of 0°C to +70°C, while the A3966ELBTR-T is specified for the extended industrial temperature range of -40°C to +85°C. Both devices are otherwise functionally identical and share the same electrical ratings and package.
Are the A3966SLBTR-T and A3966ELBTR-T pin-compatible?
Yes. Both devices are offered in the same 16-lead SOIC package with identical pin assignments. This allows the A3966ELBTR-T to be used as a drop-in replacement for the A3966SLBTR-T in applications requiring a wider operating temperature range, provided the rest of the design meets the extended temperature requirements.
What is the maximum output current rating for these devices?
Both the A3966SLBTR-T and A3966ELBTR-T are rated for a continuous output current of up to 650 mA per bridge (1.2 A peak) when properly heat-sinked. The actual achievable current depends on the PCB copper area, ambient temperature, and duty cycle, so the datasheet thermal derating curves should be consulted for the specific application.
What supply voltage range do the A3966SLBTR-T and A3966ELBTR-T support?
Both devices operate from a motor supply voltage (VS) of 4.75 V to 30 V and a logic supply voltage (VCC) of 4.75 V to 5.25 V. This makes them suitable for a wide range of stepper and DC motor applications in industrial, consumer, and automotive-adjacent designs.
Can the A3966ELBTR-T be used in place of the A3966SLBTR-T in an existing design?
Yes, the A3966ELBTR-T is functionally and pin-compatible with the A3966SLBTR-T, so it can be used as a direct substitute. However, the designer must verify that all other components in the system are also rated for the extended temperature range if the application will operate outside 0°C to +70°C.
What package do the A3966SLBTR-T and A3966ELBTR-T use?
Both devices are supplied in a 16-lead SOIC (small outline integrated circuit) package with a body width of 3.90 mm (0.154 in) and a lead pitch of 1.27 mm. The suffix "TR" indicates tape and reel packaging for automated assembly.
Do the A3966SLBTR-T and A3966ELBTR-T include internal protection features?
Yes. Both devices include internal shutdown diodes for inductive load protection, thermal shutdown circuitry, and undervoltage lockout. These features help protect the IC under fault conditions and are common to both temperature-grade variants.