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Allegro MicroSystems A6279ELWTR-T
- Part No.:
- A6279ELWTR-T
- Manufacturer:
- Allegro MicroSystems
- Category:
- LED Drivers
- Package:
- 24-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
A6279ELWTR-T.pdf
- Description:
- IC LED DRVR LINEAR 75.5MA 24SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,316
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Product details
Overview
A6279ELWTR-T from Allegro MicroSystems is a 16-channel serial-input constant-current latched LED driver with open-LED detection, designed for high-reliability LED display systems. It features 3.0–5.5 V logic supply operation, up to 90 mA per output, 20 ns output staggering delay, and CMOS serial data output for cascading. Used in industrial signage and automotive dashboard displays where fault-aware LED driving is critical.
For engineers reviewing the A6279ELWTR-T datasheet, A6279ELWTR-T pinout, A6279ELWTR-T application, or A6279ELWTR-T equivalent, key selection factors include its 24-pin SOICW package, REXT-based current programming, integrated UVLO/thermal shutdown, and OCD bit reporting via SERIAL DATA OUT - all verified for LED matrix and segment drivers requiring real-time open-circuit diagnostics.
Technical Context
The A6279ELWTR-T integrates a 16-bit CMOS shift register, parallel latches, and NPN constant-current sink drivers in a single monolithic BiCMOS IC. Its open-LED detection operates by comparing VCE against a 0.30 V threshold during test mode, returning error bits via serial shift-out on the SERIAL DATA OUT pin.
It supports two operational modes: Normal mode (serial-to-parallel latch transfer on LATCH ENABLE high) and LED OCD mode (entered via defined OE/LE clock sequencing), with thermal shutdown at 165°C and undervoltage lockout activating below 2.15–2.85 V depending on VDD slew direction.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Channels | 16 independent constant-current sink outputs (OUT0–OUT15) |
| Max Output Current | 90 mA per channel, set externally via REXT resistor |
| Logic Supply Range | 3.0–5.5 V - compatible with both 3.3 V and 5 V microcontrollers |
| Open LED Detection | 0.30 V VCE threshold; error bits returned serially via SDOUT pin |
| Staggering Delay | 20 ns typical between consecutive outputs - reduces simultaneous switching noise and EMI |
| Thermal Shutdown | 165°C junction temperature cutoff with 15°C hysteresis - preserves latch data during fault |
| Serial Data Rate | Up to 25 MHz - enables fast refresh of large LED arrays |
Pinout & Package
Package: 24-pin SOICW (wide-body SOIC), lead-free with 100% matte tin plating; 7.50 mm body width, 15.40 mm length, 2.65 mm max height; exposed thermal pad not present (LP/ET packages only).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 3, 4, 5–12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 | GND / SERIAL DATA IN / CLOCK / LATCH ENABLE / OUT0–OUT15 / OUTPUT ENABLE / SERIAL DATA OUT / REXT / LOGIC SUPPLY | Standard 24-pin SOICW pinout per Allegro datasheet Rev. 10: Pin 1 = GND, Pin 2 = SERIAL DATA IN, Pin 3 = CLOCK, Pin 4 = LATCH ENABLE, Pins 5–20 = OUT0–OUT15, Pin 21 = OUTPUT ENABLE, Pin 22 = SERIAL DATA OUT, Pin 23 = REXT, Pin 24 = LOGIC SUPPLY (VDD) |
Key Features
| Feature | Design Value |
|---|---|
| Schmitt trigger inputs | 200–400 mV hysteresis on all digital inputs - rejects noise in noisy industrial environments |
| Power-On Reset (POR) | Resets shift register and latches to zero on power-up or UVLO recovery - ensures known initial state |
| CMOS serial data output | Enables daisy-chaining of multiple A6279 devices without external logic - scales drive lines linearly |
| Internal UVLO & TSD | Prevents erratic output behavior during brownout or overtemperature - maintains system integrity without host intervention |
| Output current matching | ±6.0% max mismatch between any two outputs at same VCE - ensures uniform LED brightness across channels |
Applications
| Industrial LED Signage | Automotive Dashboard Displays |
|---|---|
Use Scenario: Outdoor variable-message signs using multiplexed 7-segment or dot-matrix LEDs under wide temperature and EMI conditions. IC Role / Device Role / Timing Role: Constant-current sink driver with open-circuit fault reporting - replaces discrete transistor arrays and current-limiting resistors. Use Value: Eliminates manual visual inspection by auto-detecting open LED strings and reporting failures via serial interface for remote diagnostics. | Use Scenario: Instrument cluster backlighting with 16-segment indicators requiring fail-safe operation and thermal resilience. IC Role / Device Role / Timing Role: Latched LED driver with staggered 20 ns output enable - minimizes ground bounce during simultaneous segment activation. Use Value: Reduces conducted EMI by 15–20 dB compared to non-staggered drivers, meeting CISPR 25 Class 3 requirements. |
| Medical Equipment Status Panels | Point-of-Sale (POS) Terminal Indicators |
Use Scenario: Critical status indicators in hospital-grade devices where LED failure must be detected before patient interaction. IC Role / Device Role / Timing Role: Open-LED detection in Test mode - performs periodic self-checks without interrupting normal display operation. Use Value: Enables IEC 62304-compliant safety monitoring by providing deterministic fault bitstream via SDOUT for host MCU validation. | Use Scenario: High-volume retail terminals with multi-color LED status rings subject to mechanical stress and vibration. IC Role / Device Role / Timing Role: Serial-input latched driver with 3.0–5.5 V logic compatibility - interfaces directly with low-voltage ARM Cortex-M0+ controllers. Use Value: Supports 25 MHz data rates for rapid reconfiguration of indicator patterns during transaction workflows. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar constant-current LED driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLC59283DBQR | 16-channel, 45 mA max per channel; no open-LED detection; uses internal current reference | Lacks diagnostic capability; suited for cost-sensitive, non-safety-critical signage | Select when open-circuit reporting is unnecessary and lower drive current suffices |
| MAX7219CWG+ | 8-digit/64-LED scan driver with SPI interface; includes BCD decode and intensity control; no REXT programming | Integrated display controller architecture - targets 7-segment numeric displays, not general-purpose LED sinks | Choose for embedded numeric displays needing built-in decoding and brightness PWM |
Compared with TLC59283DBQR and MAX7219CWG+, the A6279ELWTR-T uniquely delivers 90 mA per channel with hardware-level open-LED diagnostics and REXT-based current tuning - making it optimal for high-brightness, fault-aware LED systems where reliability outweighs integration convenience.
Availability
A6279ELWTR-T is available at Aetrix Electronics and suitable for industrial signage, automotive dashboard displays, and medical equipment status panels requiring stable component supply and long-term production continuity.
Supply support for A6279ELWTR-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, headquartered in Worcester, Massachusetts.
The A6279 product line was engineered specifically for robust LED display driving in harsh environments - emphasizing fault detection, thermal resilience, and noise-immune serial control for industrial and transportation applications.
FAQ
What is the maximum allowable output current per channel for the A6279ELWTR-T?
The A6279ELWTR-T supports up to 90 mA per output channel, determined by the external REXT resistor value. At REXT = 225 Ω and VCE = 0.7 V, typical current is 75.5 mA; at REXT = 470 Ω, it drops to 40.0 mA. The absolute maximum rating is 90 mA, validated across operating temperature range –40°C to +85°C.
How does open-LED detection work on the A6279ELWTR-T?
The A6279ELWTR-T detects open LEDs by measuring VCE voltage during LED OCD mode: if VCE falls below 0.30 V while the output is enabled, a '0' error bit is set in the shift register. These bits are then clocked out serially via the SERIAL DATA OUT pin after three CLOCK pulses with OUTPUT ENABLE held low - enabling host MCU-based fault mapping without additional sensing circuitry.
Can the A6279ELWTR-T operate with a 3.3 V microcontroller interface?
Yes, the A6279ELWTR-T fully supports 3.3 V logic levels: its VIH threshold is 0.7×VDD (min 2.31 V at VDD = 3.3 V), VIL is 0.3×VDD (max 0.99 V), and input hysteresis is 200–400 mV. All digital pins - SERIAL DATA IN, CLOCK, LATCH ENABLE, and OUTPUT ENABLE - are compatible with standard 3.3 V CMOS outputs without level shifting.
What thermal protection features does the A6279ELWTR-T include?
The A6279ELWTR-T incorporates thermal shutdown (TSD) that disables outputs at 165°C junction temperature, with 15°C hysteresis for recovery. During TSD, shift registers and latches retain their data - eliminating need for host reinitialization. In LED OCD mode, TSD forces all shift register bits to '0', ensuring consistent fault-state signaling even under thermal stress.
Is the A6279ELWTR-T pin-compatible with other A6279 variants like A6279ELPTR-T?
Yes, all A6279 variants - including A6279ELWTR-T (SOICW), A6279ELPTR-T (TSSOP-LP), and A6279EETTR-T (QFN-ET) - share identical 24-pin functional pinouts and electrical characteristics. Only package dimensions, thermal pad presence, and mounting method differ; PCB layout must be adapted per JEDEC footprint (MS-013 AD for SOICW, MO-153 ADT for TSSOP, etc.), but signal routing remains interchangeable.
A6279ELWTR-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Allegro MicroSystems
- Series:
- -
- Package/Case:
- 24-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Linear
- Topology:
- Shift Register
- Internal Switch(s):
- Yes
- Number of Outputs:
- 16
- Voltage - Supply (Min):
- 3V
- Voltage - Supply (Max):
- 5.5V
- Voltage - Output:
- -
- Current - Output / Channel:
- 75.5mA
- Frequency:
- 25MHz
- Dimming:
- -
- Applications:
- -
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-SOIC
A6279ELWTR-T FAQ
1.How can I place an order for A6279ELWTR-T through Aetrix?
Please submit a Request for Quotation (RFQ) for A6279ELWTR-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 A6279ELWTR-T reliable?
The price and inventory of A6279ELWTR-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for A6279ELWTR-T is usually 5 days.
3.What payment methods are accepted for A6279ELWTR-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for A6279ELWTR-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for A6279ELWTR-T?
A6279ELWTR-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your A6279ELWTR-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 A6279ELWTR-T?
For technical support, including A6279ELWTR-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your A6279ELWTR-T requirements.
6.How does Aetrix verify that A6279ELWTR-T is sourced from the original manufacturer or authorized distributors?
All A6279ELWTR-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 A6279ELWTR-T meets industry standards.
7.What is the process for return or replacement of A6279ELWTR-T?
All A6279ELWTR-T units undergo pre-shipment inspection (PSI). If there is an issue with A6279ELWTR-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 A6279ELWTR-T part is unused and in its original packaging.
Return procedure for A6279ELWTR-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
A6279ELWTR-T Tags
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