Part A
A3966SLB
Allegro MicroSystems
- Lifecycle
- Active
- Stock
- 3540 Stückzahl
- Package
- SOIC-16
- Series
- PMIC Motor Treiber, Controller
Replacement verdict
Compatible functional replacement candidate
The A3966SLB and A3966ELBTR-T are functionally equivalent dual full-bridge PWM motor drivers from Allegro MicroSystems, sharing the same circuit topology, supply voltage range, output current capability, and logic interface. The A3966ELBTR-T is the automotive-grade variant supplied in a tape-and-reel package, making it a viable replacement for the A3966SLB in most applications, provided the operating temperature and qualification requirements are validated against the target design.
Output Current Rating
High match
Supply Voltage Range
High match
Package Type
High match
Operating Temperature Range
Validation required
Parts at a glance
Part B
A3966ELBTR-T
Allegro MicroSystems
- Lifecycle
- Active
- Stock
- 3607 Stückzahl
- Package
- SOIC-50
- Series
- PMIC Motor Treiber, Controller
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | A3966SLB | A3966ELBTR-T | Why it matters |
|---|---|---|---|
| Motor Type | Bipolar Stepper | Bipolar Stepper | Both devices must drive the same motor type to be functionally interchangeable. |
| Output Configuration | Dual Full-Bridge | Dual Full-Bridge | Matching output topology ensures the same load-driving capability and wiring scheme. |
| Supply Voltage (Min) | 4.75 V | 4.75 V | Minimum operating voltage determines compatibility with the system power rail. |
| Supply Voltage (Max) | 5.25 V | 5.25 V | Maximum operating voltage must not be exceeded to avoid damaging the driver. |
| Output Current per Channel | 750 mA | 750 mA | Current rating defines the maximum load the driver can handle per bridge. |
| Mounting Type | Surface Mount | Surface Mount | Same mounting style ensures physical compatibility with the PCB footprint. |
| Package / Case | 16-PowerSOIC (0.295", 7.50mm Width) | 16-PowerSOIC (0.295", 7.50mm Width) | Package must match for drop-in replacement on the existing board layout. |
| Operating Temperature Range | -20°C to +85°C | -40°C to +85°C | Wider temperature range affects suitability for industrial or automotive environments. |
| Packaging | Tube | Tape & Reel | Packaging affects assembly line compatibility and handling requirements. |
| Part Status | Obsolete | Active | Active status ensures long-term availability and support for production. |
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 | A3966SLB | A3966ELBTR-T |
|---|---|---|
| Part Status | Obsolete | 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 A3966SLB and A3966ELBTR-T?
The A3966SLB and A3966ELBTR-T are dual full-bridge motor driver ICs from Allegro MicroSystems designed to drive bipolar stepper motors or two DC motors. Both devices integrate dual H-bridges with internal PWM current control, clamp diodes, and logic-level inputs for direct interfacing with microcontrollers.
What is the difference between the A3966SLB and A3966ELBTR-T?
The primary difference is the package and temperature grade. The A3966SLB is supplied in a 16-pin SOIC-W (batwing) package, while the A3966ELBTR-T is supplied in a 16-pin TSSOP package with tape-and-reel packaging. The "E" suffix in A3966ELBTR-T indicates an extended temperature range of -40°C to +85°C, whereas the A3966SLB is rated for -20°C to +85°C.
Are the A3966SLB and A3966ELBTR-T electrically identical?
Yes, both devices share the same electrical core: dual full-bridge outputs rated at 30 V and ±750 mA continuous per bridge, internal fixed off-time PWM current control, and logic supply range of 4.5 V to 5.5 V. The functional behavior and register interface are identical across both part numbers.
Can the A3966SLB and A3966ELBTR-T be used interchangeably in a design?
Not directly without PCB redesign. The A3966SLB uses a 16-pin SOIC-W package with a 7.50 mm body width, while the A3966ELBTR-T uses a 16-pin TSSOP with a 4.40 mm body width. The land patterns, thermal performance, and pin pitch differ, so the PCB footprint must be updated accordingly.
What is the operating temperature range for each device?
The A3966SLB is specified for operation from -20°C to +85°C ambient temperature. The A3966ELBTR-T is specified for operation from -40°C to +85°C ambient temperature, making it suitable for industrial and automotive-adjacent applications requiring wider temperature tolerance.
What motor types can these drivers control?
Both devices are designed to drive bipolar stepper motors in full-step, half-step, and microstepping modes, as well as two independent DC brush motors. The dual full-bridge architecture allows each bridge to be controlled independently via the logic inputs.
What is the maximum output current per bridge for these devices?
Both the A3966SLB and A3966ELBTR-T are rated for ±750 mA continuous output current per bridge, with peak currents up to ±1.5 A. The actual achievable current depends on the PCB thermal design, ambient temperature, and duty cycle.
Do these devices require external components for current control?
Yes. Both devices require external sense resistors connected to the SENSE pins to set the PWM current limit, along with external capacitors for the charge pump and logic supply bypassing. The internal PWM current control uses a fixed off-time scheme, so no external oscillator is needed.