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Allegro MicroSystems A2919SLB-T
- Part No.:
- A2919SLB-T
- Manufacturer:
- Allegro MicroSystems
- Category:
- Motor Drivers, Controllers
- Package:
- 24-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
A2919SLB-T.pdf
- Description:
- IC MOTOR DRIVER BIPOLAR 24SOIC
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
A2919SLB-T from Allegro MicroSystems is a dual full-bridge PWM motor driver IC designed to control two DC motors bidirectionally or drive both windings of a bipolar stepper motor. It supports 45 V motor supply voltage, delivers up to ±750 mA continuous output current per bridge, and features internal PWM current regulation with selectable 0%/41%/67%/100% current limits via logic inputs I0 and I1. It is used in precision motion control systems requiring half- or quarter-step microstepping.
For engineers reviewing the A2919SLB-T datasheet, A2919SLB-T pinout, A2919SLB-T application, or A2919SLB-T equivalent, key selection considerations include its 24-pin SOICW package with exposed thermal tabs, integrated clamp/flyback diodes, fixed off-time PWM control (46 μs typical), thermal shutdown at 170°C, and compatibility with microprocessor-based current-stepping sequences.
Technical Context
The A2919SLB-T integrates two independent H-bridge drivers with internal PWM current regulation per channel, using external RC timing components (RT/CT) to set fixed off-time (46 μs typical) and an external sense resistor (RS) to define peak current via VREF/10 RS scaling. Each bridge includes source/sink drivers with <1.5 V total saturation voltage at ±750 mA and built-in ground-clamp and flyback diodes.
Logic-level PHASE inputs determine current direction per bridge, while I0/I1 inputs digitally select four current-limit thresholds. Internal dead-time (~2 μs) prevents shoot-through during direction switching, and thermal shutdown disables all outputs at TJ = 170°C, re-enabling at 145°C. No special power-up sequencing is required.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Motor Supply Voltage | Up to 45 V - enables direct interface with industrial 24–40 V DC bus systems without level-shifting. |
| Continuous Output Current | ±750 mA per bridge - supports moderate-torque stepper or dual DC motor loads without external heatsinking under typical ambient conditions. |
| Output Saturation Voltage | ≤1.5 V (source) + ≤1.2 V (sink) at ±750 mA - minimizes conduction loss and self-heating during sustained operation. |
| PWM Fixed Off-Time | 46 μs typical (RT = 56 kΩ, CT = 820 pF) - ensures current chopping remains above audible range while enabling stable regulation for inductive loads ≥3 mH. |
| Thermal Shutdown Threshold | 170°C junction temperature - provides fail-safe protection against thermal runaway during overload or poor PCB thermal design. |
| Current Limit Selection | Four discrete levels (0%, 41%, 67%, 100%) via I0/I1 logic inputs - enables microstepping torque matching and hold/start current optimization in firmware-controlled drives. |
Pinout & Package
Package: 24-pin SOICW (suffix LB) with exposed thermal tabs - batwing construction enhances thermal dissipation (θJA = 55°C/W), supporting simultaneous dual-bridge operation at rated current.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VBB (Pin 1) | Motor supply input | High-voltage rail connection for both bridges; must be decoupled near package with ≥10 μF low-ESR capacitor. |
| GND (Pins 2–5, 18–19) | Power ground | Multiple dedicated ground pins reduce common-impedance coupling and improve current return path integrity. |
| OUT1A/OUT1B (Pins 6, 7) | Bridge 1 output terminals | Drive one winding of bipolar stepper or one DC motor; internally fused pair (pins 6 & 7). |
| PHASE1 (Pin 8) | Bridge 1 direction control | Logic-level input defining current flow direction; internal 2 μs dead-time prevents shoot-through during transitions. |
| VREF1 (Pin 9) | Bridge 1 current reference | Analog input setting peak current threshold via ITRIP = VREF1 / (10 × RS); range 1.0–7.5 V. |
| SENSE1 (Pin 10) | Bridge 1 current sense input | Connects to external sense resistor (RS); comparator monitors VS to trigger PWM off-cycle. |
| I0/I1 (Pins 11, 12) | Digital current limit select | Two-bit logic inputs selecting 0%/41%/67%/100% of max current; high-high disables all drivers. |
| VCC (Pin 13) | Logic supply | 4.75–5.25 V digital supply; powers internal logic, comparators, and PWM circuitry. |
| RC1/RC2 (Pins 14, 15) | PWM timing reference | Connect to RT/CT network; sets fixed off-time (toff = RT × CT) for current decay control. |
| OUT2A/OUT2B (Pins 16, 17) | Bridge 2 output terminals | Drive second winding or second DC motor; internally fused pair (pins 18 & 19). |
| PHASE2/VREF2/SENSE2 (Pins 20–22) | Bridge 2 control signals | Functionally identical to Bridge 1 counterparts; enables independent current/direction control per channel. |
| CC/CT/RT (Pins 23, 24) | Timing network connections | Support external RC network for Bridge 2 PWM off-time; CC is bypass capacitor connection point. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated clamp and flyback diodes | Eliminates need for 4 external diodes per bridge, reducing BOM count and PCB area while protecting against inductive kickback. |
| Independent PWM current control per bridge | Enables asymmetric current profiles-e.g., higher torque on one phase during acceleration, lower hold current on both phases. |
| Digital current limit selection (I0/I1) | Allows firmware-driven microstepping sequences (half/quarter-step) without analog DACs or external current-setting DACs. |
| Batwing SOICW package with thermal tabs | Provides 55°C/W junction-to-ambient thermal resistance-enables full 750 mA per bridge in compact industrial layouts. |
| Internal thermal shutdown with hysteresis | Shuts down at 170°C and recovers at 145°C-prevents latch-up during transient overloads while allowing automatic recovery after cooling. |
Applications
| Industrial Stepper Positioning | Medical Infusion Pump Drive |
|---|---|
|
Use Scenario: Precision open-loop positioning of X-Y stages in CNC engraving equipment using 1.8° bipolar stepper motors. IC Role / Device Role / Timing Role: Dual-bridge driver executing half-step and quarter-step sequences under µP control; regulates winding current to maintain torque consistency across step positions. Use Value: Digital I0/I1 current selection eliminates analog trimming, enabling consistent 67% torque reduction when both phases are energized-critical for smooth motion and reduced resonance. |
Use Scenario: Bidirectional peristaltic pump actuation in portable IV infusion devices requiring precise flow rate control and safety-critical stall detection. IC Role / Device Role / Timing Role: Dual H-bridge driving two DC motors-one for pump roller advancement, one for pressure-sensing feedback mechanism. Use Value: Integrated thermal shutdown (170°C) and low saturation voltage (<1.8 V total) ensure safe operation within sealed enclosures and extend battery life during continuous low-duty-cycle operation. |
| Automated Test Equipment (ATE) Actuators | Lab Automation Sample Handler |
|
Use Scenario: High-reliability linear actuators in semiconductor probe stations requiring repeatable sub-micron positioning and rapid direction reversal. IC Role / Device Role / Timing Role: Bipolar stepper driver implementing microstepping with externally tuned RC timing (46 μs off-time) to suppress audible noise and mechanical vibration. Use Value: Fixed off-time PWM architecture avoids variable-frequency artifacts that interfere with sensitive electrical measurements during wafer probing. |
Use Scenario: Multi-axis robotic arm in automated ELISA plate handlers moving pipette tips between wells with minimal vibration-induced cross-contamination. IC Role / Device Role / Timing Role: Dual full-bridge controlling two stepper motors-one for horizontal translation, one for vertical lift-synchronized via shared VREF and µP logic. Use Value: Independent current sensing (SENSE1/SENSE2) allows real-time stall detection on either axis, triggering immediate fault halt without host µP intervention. |
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 4.5 A peak current, external MOSFET drivers, no integrated clamp diodes, requires 6 external diodes. | Targets high-power stepper systems (>1 A); lacks integrated current-sense regulation and digital current scaling. | Select when >1 A per phase is required and board space allows discrete power stage layout. |
| DRV8825 | Microstepping up to 1/32-step, integrated current DAC, 2.2 A peak, but only single H-bridge per IC (dual ICs needed). | Designed for compact, high-resolution stepper control; requires two units and additional logic for dual-winding coordination. | Select for new designs prioritizing fine microstepping resolution and lower system-level BOM cost over single-package integration. |
Compared with TB6600HG and DRV8825, the A2919SLB-T offers true single-package dual-bridge integration with embedded PWM regulation, digital current scaling, and thermal protection-making it optimal for space-constrained, moderate-current applications where reliability and design simplicity outweigh ultra-fine stepping or extreme current capability.
Availability
A2919SLB-T is available at Aetrix Electronics and suitable for industrial motion control, medical device actuation, and automated test equipment requiring stable component supply despite its Last Time Buy status.
Supply support for A2919SLB-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 sensing and power IC solutions, founded in 1989 and headquartered in Worcester, Massachusetts.
The A2919SLB-T belongs to Allegro's legacy motor driver product line, engineered specifically for robust, integrated dual-H-bridge control in cost-sensitive industrial and instrumentation applications where thermal resilience and analog-digital hybrid current regulation are essential.
FAQ
What is the maximum continuous current rating per bridge for the A2919SLB-T?
The A2919SLB-T supports ±750 mA continuous output current per bridge under specified thermal conditions (TA ≤ 85°C, adequate PCB copper pour). This rating assumes use of the exposed thermal tab in the LB package and proper heatsinking. Peak current is ±1.0 A for pulses ≤20 μs. Exceeding 750 mA continuously risks thermal shutdown activation unless ambient and layout conditions are significantly improved.
Does the A2919SLB-T require external flyback diodes?
No, the A2919SLB-T does not require external flyback diodes. It integrates internal clamp and flyback diodes for both bridges, as confirmed in the Applications Information section and Features list. These diodes protect against inductive transients from stepper motor windings or DC motor back-EMF, eliminating four external diodes per bridge and simplifying layout.
How is PWM current regulation implemented in the A2919SLB-T?
The A2919SLB-T uses fixed off-time PWM current regulation: an internal comparator monitors voltage across an external sense resistor (RS), triggering a monostable multivibrator when the threshold (VREF/10 RS) is reached. The source driver then turns off for a user-defined time (toff = RT × CT), after which conduction resumes. This cycle maintains average winding current at the selected level.
What does the 'LB' suffix indicate in A2919SLB-T?
'LB' denotes the 24-pin SOICW package with exposed thermal tabs (batwing construction), optimized for enhanced thermal performance (θJA = 55°C/W). This suffix distinguishes it from other variants like 'LP' (plastic DIP) and confirms the presence of thermal pads on the underside for soldering to PCB copper planes-critical for sustaining 750 mA per bridge.
Is the A2919SLB-T still recommended for new designs?
No-the A2919SLB-T is classified as Last Time Buy with a final order deadline of October 29, 2010. Allegro explicitly states it should not be purchased for new design applications due to imminent obsolescence. While Aetrix Electronics supports legacy procurement for existing programs, new designs should evaluate alternatives such as DRV8825 or TB6600HG based on current requirements.
A2919SLB-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Allegro MicroSystems
- Series:
- -
- Package/Case:
- 24-SOIC (0.295", 7.50mm Width)
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Motor Type - Stepper:
- Bipolar
- 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:
- 1/2, 1/4
- Applications:
- General Purpose
- Current - Output:
- 750mA
- Voltage - Supply:
- 4.75V ~ 5.25V
- Voltage - Load:
- 10V ~ 45V
- Operating Temperature:
- -20°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-SOIC
A2919SLB-T FAQ
1.How can I place an order for A2919SLB-T through Aetrix?
Please submit a Request for Quotation (RFQ) for A2919SLB-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 A2919SLB-T reliable?
The price and inventory of A2919SLB-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for A2919SLB-T is usually 5 days.
3.What payment methods are accepted for A2919SLB-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for A2919SLB-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for A2919SLB-T?
A2919SLB-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your A2919SLB-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 A2919SLB-T?
For technical support, including A2919SLB-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your A2919SLB-T requirements.
6.How does Aetrix verify that A2919SLB-T is sourced from the original manufacturer or authorized distributors?
All A2919SLB-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 A2919SLB-T meets industry standards.
7.What is the process for return or replacement of A2919SLB-T?
All A2919SLB-T units undergo pre-shipment inspection (PSI). If there is an issue with A2919SLB-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 A2919SLB-T part is unused and in its original packaging.
Return procedure for A2919SLB-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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