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Allegro MicroSystems A3968SLB-T
- Part No.:
- A3968SLB-T
- Manufacturer:
- Allegro MicroSystems
- Category:
- Motor Drivers, Controllers
- Package:
- 16-PowerSOIC (0.295", 7.50mm Width)
- Datasheet:
-
A3968SLB-T.pdf
- Description:
- IC MOTOR DRVR 4.75V-5.5V 16SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,907
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Product details
Overview
A3968SLB-T from Allegro MicroSystems is a discontinued dual full-bridge PWM motor driver IC designed to bidirectionally control two DC motors in embedded motion systems. It delivers ±650 mA continuous output current per bridge, supports up to 30 V load supply voltage, and integrates fixed-frequency PWM current control with user-selectable blanking via external RC network. Used in industrial actuators and small robotic platforms requiring dynamic braking and thermal protection.
For engineers reviewing the A3968SLB-T datasheet, A3968SLB-T pinout, A3968SLB-T application, or A3968SLB-T equivalent, key selection considerations include its Satlington® sink drivers, brake-mode operation, internal crossover-current and UVLO protection, and SOIC-16W package with fused thermal pads - all critical for legacy design support and replacement analysis.
Technical Context
The A3968SLB-T implements two independent full-bridge outputs with source/sink driver pairs controlled by INPUTA/INPUTB logic states. Each bridge features internal PWM current regulation using a fixed-frequency oscillator (22.9–27.9 kHz) set by external RT/CT components and blanking time derived from CT (tblank = 1900 × CT µs).
Current sensing uses an external resistor (RS) and reference voltage (VREF ≤ 2.0 V), with trip threshold defined as ITRIP = VREF/(4RS) + ISO (ISO = 12–24 mA). Brake mode disables both source drivers and enables both sink drivers simultaneously, shorting motor terminals for dynamic deceleration without current regulation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | ±650 mA continuous per bridge; peak ±750 mA limited by thermal design and duty cycle |
| Supply Voltage | VBB = 30 V max; VCC = 4.75–5.5 V logic supply; supports 24 V motor systems |
| PWM Frequency | 22.9–27.9 kHz (typ. 25.4 kHz with 56 kΩ/680 pF RC); determines current ripple and switching loss trade-off |
| Saturation Voltage | Sink driver: 0.3–1.3 V at 400–650 mA; enables low-loss recirculation during PWM off-time |
| Thermal Protection | Internal shutdown at TJ = 165 °C (typ.), with 15 °C hysteresis; prevents permanent damage under overload |
| Logic Inputs | CMOS-compatible; INPUTA/INPUTB truth table defines forward/reverse/brake/disable states per bridge |
| Protection Features | UVLO (4.1–4.6 V enable threshold), crossover-current dead time (0.2–3.0 µs), ground-clamp & flyback diodes |
Pinout & Package
Package: 16-pin SOICW (suffix LB), with pins 4 and 13 internally fused to die pad for enhanced thermal dissipation; Pb-free, matte tin leadframe plating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VBB | Motor supply input | High-side power rail for both bridges; requires local 47 µF electrolytic decoupling |
| VCC | Logic supply input | 5 V digital supply; powers internal logic, reference, and PWM circuitry |
| INPUT1A / INPUT1B INPUT2A / INPUT2B | Bridge direction control inputs | CMOS-level logic inputs defining polarity and state (forward/reverse/brake/disable) for each motor |
| OUT1A / OUT1B OUT2A / OUT2B | Full-bridge output terminals | Drive motor windings directly; sink drivers use Satlington® structure for low VCE(SAT) |
| VREF | Current-limit reference input | Analog input (0.1–2.0 V) setting trip threshold via ITRIP = VREF/(4RS) + ISO |
| RC | Oscillator timing node | Connects external RT/CT network; sets PWM frequency and blanking window duration |
| SENSE | Current-sense feedback | Inputs voltage drop across external RS; compared against scaled VREF for PWM current limiting |
| GND | Power and signal ground | Common return for VBB, VCC, logic, and sense paths; pins 4 & 13 tied to die pad |
Key Features
| Feature | Design Value |
|---|---|
| Satlington® sink drivers | Combines low saturation voltage (0.3 V @ 400 mA) with high peak current capability (±750 mA), reducing heat generation during PWM recirculation |
| User-selectable blanking window | Blanking time (1.3 µs nominal) prevents false PWM latch reset from switching transients, ensuring stable current regulation |
| Integrated brake mode | Simultaneous activation of both sink drivers per bridge shorts motor terminals, enabling rapid dynamic deceleration without external components |
| Internal thermal shutdown | Automatically disables all outputs at 165 °C junction temperature with 15 °C hysteresis, protecting against sustained overloads or poor heatsinking |
| Crossover-current protection | 1.8 µs typical dead time between source/sink switching prevents shoot-through current spikes during direction reversal |
Applications
| Industrial Actuators | Small Robotic Platforms |
|---|---|
Use Scenario: Precision linear actuation in valve positioning and automated test equipment requiring bidirectional motion and hold torque. IC Role / Device Role / Timing Role: Dual full-bridge driver providing independent PWM-controlled current to two solenoid or DC gearmotor actuators. Use Value: ±650 mA drive capability and integrated brake mode enable precise stop-and-hold functionality without external braking circuits. | Use Scenario: Differential drive for compact wheeled robots where space-constrained PCBs require integrated dual-motor control. IC Role / Device Role / Timing Role: Motor interface IC translating microcontroller GPIO signals into H-bridge drive with current regulation and fault protection. Use Value: SOIC-16W package with fused thermal pads allows reliable operation at ambient temperatures up to 85 °C in enclosed chassis. |
| Office Automation Devices | Medical Fluid Pumps |
Use Scenario: Paper feed and document handling mechanisms in multifunction printers needing quiet, controllable bidirectional motion. IC Role / Device Role / Timing Role: Current-regulated motor driver managing speed and torque of DC paper transport motors via PWM duty cycle. Use Value: Fixed-frequency PWM (25.4 kHz) operates above audible range, eliminating motor whine while maintaining efficient current control. | Use Scenario: Peristaltic pump control in portable diagnostic instruments requiring accurate flow rate and fail-safe shutdown. IC Role / Device Role / Timing Role: Safety-critical motor driver with UVLO, thermal shutdown, and current limiting to prevent overheating or uncontrolled delivery. Use Value: Internal protection features eliminate need for external monitoring circuitry, reducing BOM count and board area in Class II medical designs. |
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 |
|---|---|---|---|
| TB6612FNG | Higher continuous current (1.2 A per channel), lower VCC range (2.7–5.5 V), no internal blanking control - requires external timing design | Supports higher-power motors and battery-powered systems; lacks integrated brake-mode optimization for dynamic deceleration | Select when higher output current and wider logic supply range are required, and external RC tuning is acceptable |
| DRV8833 | Lower voltage rating (10.8 V max), integrated current regulation disabled by default, smaller 16-pin QFN package with exposed thermal pad | Better suited for low-voltage portable devices; requires external current-sense resistors and configuration for closed-loop control | Select for space-constrained, low-voltage (<12 V) applications where thermal performance via QFN package is prioritized over legacy SOIC compatibility |
Compared with A3968SLB-T, TB6612FNG offers higher current headroom but demands more external design effort for blanking and timing, while DRV8833 trades voltage capability for compactness and lower system voltage - neither is pin-compatible, and both require layout and firmware adaptation.
Availability
A3968SLB-T is available at Aetrix Electronics and suitable for industrial actuators, small robotic platforms, and office automation devices requiring stable component supply despite end-of-life status.
Supply support for A3968SLB-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 Hall-effect sensors, motor drivers, and power ICs focused on motion control and energy-efficient systems.
The A3968 product line was engineered for cost-sensitive, thermally constrained dual-motor applications in industrial and consumer equipment, emphasizing integrated protection, predictable current regulation, and SOIC packaging for ease of assembly and thermal management.
FAQ
Is A3968SLB-T still in production?
No, A3968SLB-T is a discontinued product. Allegro MicroSystems ceased production as of September 9, 2022. It is not recommended for new designs, and samples are no longer available. Aetrix Electronics maintains limited legacy stock for existing production continuity and repair programs.
What does the "LB" suffix indicate in A3968SLB-T?
The "LB" suffix denotes the 16-pin SOICW (wide-body) package with pins 4 and 13 internally fused to the die pad for improved thermal conduction. This variant is optimized for higher ambient temperature operation (–20 to 85 °C) and enhanced power dissipation compared to standard SOIC variants.
How does the A3968SLB-T implement current limiting?
The A3968SLB-T uses internal fixed-frequency PWM current control. It compares the voltage across an external sense resistor (RS) to a trip threshold derived from VREF (ITRIP = VREF/(4RS) + ISO). When current reaches this threshold, the source driver turns off; current recirculates through the sink driver and clamp diodes until the next oscillator cycle.
Can A3968SLB-T drive stepper motors?
No, A3968SLB-T is not designed for stepper motor control. It provides two independent full-bridges for bidirectional DC motor control only. Stepper applications require phase sequencing, microstepping, and often higher current per winding - capabilities not supported by the A3968SLB-T's architecture or control logic.
What protection features are built into A3968SLB-T?
A3968SLB-T includes UVLO (4.1–4.6 V enable threshold), thermal shutdown (165 °C typical), crossover-current dead time (0.2–3.0 µs), internal ground-clamp and flyback diodes, and brake-mode current limiting. These features protect against supply faults, overheating, shoot-through, inductive kickback, and uncontrolled motor current during braking.
A3968SLB-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Allegro MicroSystems
- Series:
- -
- Package/Case:
- 16-PowerSOIC (0.295", 7.50mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Motor Type - Stepper:
- -
- Motor Type - AC, DC:
- Brushed 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
A3968SLB-T FAQ
1.How can I place an order for A3968SLB-T through Aetrix?
Please submit a Request for Quotation (RFQ) for A3968SLB-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 A3968SLB-T reliable?
The price and inventory of A3968SLB-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for A3968SLB-T is usually 5 days.
3.What payment methods are accepted for A3968SLB-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for A3968SLB-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for A3968SLB-T?
A3968SLB-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your A3968SLB-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 A3968SLB-T?
For technical support, including A3968SLB-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your A3968SLB-T requirements.
6.How does Aetrix verify that A3968SLB-T is sourced from the original manufacturer or authorized distributors?
All A3968SLB-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 A3968SLB-T meets industry standards.
7.What is the process for return or replacement of A3968SLB-T?
All A3968SLB-T units undergo pre-shipment inspection (PSI). If there is an issue with A3968SLB-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 A3968SLB-T part is unused and in its original packaging.
Return procedure for A3968SLB-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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