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Allegro MicroSystems A6276SLWTR
- Part No.:
- A6276SLWTR
- Manufacturer:
- Allegro MicroSystems
- Category:
- LED Drivers
- Package:
- 24-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
A6276SLWTR.pdf
- Description:
- IC LED DRVR LINEAR 75.5MA 24SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,866
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Product details
Overview
A6276SLWTR from Allegro MicroSystems is a 16-bit serial-input, constant-current latched LED driver in 24-pin SOICW package, featuring 16 NPN sink drivers with user-adjustable current (up to 90 mA per output), undervoltage lockout, and CMOS serial data output for cascading. It interfaces directly with microprocessors at up to 20 MHz serial data rate and supports inter-digit blanking via active-low ENABLE input - ideal for multiplexed LED signage and panel displays.
For engineers reviewing the A6276SLWTR datasheet, A6276SLWTR pinout, A6276SLWTR application, or A6276SLWTR equivalent, key selection criteria include its –20°C to +85°C ambient operating range, REXT-based current programming, 85°C/W thermal resistance (SOICW), and compatibility with LED forward voltages from 1.2 V to 4.0 V in high-reliability display systems.
Technical Context
The A6276SLWTR integrates a 16-bit CMOS shift register, parallel latches, and 16 matched NPN constant-current sink drivers - all sharing a single logic ground and power ground. Its serial-to-parallel conversion is triggered by LATCH ENABLE high, while OUTPUT ENABLE (active low) provides global blanking without affecting latch state.
Current regulation is set externally via REXT (pin 23), enabling precise per-output current control across temperature; undervoltage lockout activates below 3.4 V VDD to prevent erratic operation. The device supports daisy-chaining via CMOS SERIAL DATA OUT (pin 22), maintaining signal integrity up to 10 MHz clock frequency with 50 ns minimum clock pulse width.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Configuration | 16-channel NPN constant-current sink drivers, each programmable via single REXT resistor |
| Max Output Current | 90 mA per channel continuous at TA = 85°C, VCE = 0.75 V (DIP package); SOICW derates per thermal resistance |
| Logic Supply Voltage | 4.5–5.5 V (VDD), with undervoltage lockout active below 3.4 V to prevent metastable behavior |
| Serial Data Rate | Up to 20 MHz typical at 5 V logic supply - enables fast LED refresh in high-resolution displays |
| Propagation Delay | 300–1000 ns (tpLH/tpHL) from CLOCK/LATCH/ENABLE to output - ensures tight timing control in multiplexed systems |
| Thermal Resistance | RθJA = 85°C/W (SOICW, 1-layer JEDEC PCB) - requires thermal-aware layout for sustained 90 mA operation |
| Operating Temperature | –20°C to +85°C ambient - validated for indoor signage and industrial HMI applications |
Pinout & Package
24-pin SOICW (Small Outline Integrated Circuit Wide-body) package with gull-wing leads, 1.27 mm pitch, and exposed pad not present (unlike LP variant). Pin 1 marked by notch or dot; lead finish is 100% matte tin, Pb-free.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | GND | Common reference for logic and power grounds - critical for noise immunity in shared-ground layouts |
| 2 | SERIAL DATA IN | CMOS-level serial input to shift register - data sampled on rising edge of CLOCK |
| 3 | CLOCK | Edge-triggered clock for shift register - minimum 50 ns pulse width required |
| 4 | LATCH ENABLE | Active-high strobe that transfers shift register contents to output latches - enables synchronous update |
| 5–20 | OUT0–OUT15 | 16 NPN open-collector sink outputs - each delivers constant current set by REXT (pin 23) |
| 21 | OUTPUT ENABLE | Active-low global blanking control - disables all outputs without altering latch state |
| 22 | SERIAL DATA OUT | CMOS-level serial output for cascading multiple A6276 devices - supports extended display width |
| 23 | REXT | External current-setting resistor connection - sets identical sink current for all 16 outputs |
| 24 | SUPPLY (VDD) | 5 V logic supply input - powers CMOS logic, latches, and bias circuitry; includes UVLO protection |
Key Features
| Feature | Design Value |
|---|---|
| Constant-current sink outputs | Matched ±1.5% current between any two outputs at same VCE - ensures uniform LED brightness across segments |
| Undervoltage lockout (UVLO) | Activates below 3.4 V VDD - prevents partial register updates and output glitches during brownout conditions |
| Cascadable serial interface | CMOS SERIAL DATA OUT (pin 22) drives next device's SERIAL DATA IN - eliminates need for external level-shifting |
| Inter-digit blanking support | Active-low OUTPUT ENABLE (pin 21) blanks all outputs synchronously - essential for time-multiplexed LED arrays |
| Low-power CMOS logic core | IDD(OFF) ≤ 1.4 mA at VDD = 5 V, OE = high - minimizes standby power in always-on display controllers |
Applications
| LED Signage Panels | Industrial HMI Displays |
|---|---|
|
Use Scenario: Outdoor alphanumeric LED signs using multiplexed 7-segment or dot-matrix modules with high ambient light rejection requirements. IC Role / Device Role / Timing Role: Constant-current sink driver providing synchronized digit-by-digit blanking and brightness control via REXT and OUTPUT ENABLE. Use Value: Delivers stable 75.5 mA typical output current per segment at VCE = 0.7 V, enabling high-brightness red/amber LEDs without thermal runaway. |
Use Scenario: Factory-floor operator panels with 16-segment status indicators and alarm lights requiring long-term reliability under vibration and temperature cycling. IC Role / Device Role / Timing Role: Serial-input LED driver interfacing directly with PLC or microcontroller GPIOs, using LATCH ENABLE for deterministic frame updates. Use Value: Matches output currents within ±1.5% across channels, eliminating visible brightness variation between adjacent status LEDs over –20°C to +85°C. |
| Point-of-Sale Terminals | Transportation Annunciators |
|
Use Scenario: Compact retail terminals with dual-line LED displays showing price, item code, and transaction status in space-constrained PCB layouts. IC Role / Device Role / Timing Role: Space-efficient 24-pin SOICW driver replacing discrete transistor arrays - reduces BOM count and layout area. Use Value: Supports 20 MHz serial input rate and 10 MHz cascade clock, enabling full 32-character display refresh at >120 Hz without microcontroller overhead. |
Use Scenario: Bus/train destination displays using cascaded LED modules where EMI resilience and thermal stability are critical in enclosed enclosures. IC Role / Device Role / Timing Role: Daisy-chainable constant-current driver with integrated UVLO - prevents display corruption during vehicle battery voltage dips. Use Value: Maintains regulated output current down to VDD = 4.5 V and rejects ground bounce via dedicated GND pin (pin 1), ensuring flicker-free operation. |
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 |
|---|---|---|---|
| TB62706BN | 8-bit architecture, no UVLO, higher RθJA (100°C/W), DIP-only packaging | Limited to smaller displays; lacks thermal headroom for sustained 90 mA operation in SOIC | Select only for legacy 8-bit designs where board space and thermal margin allow |
| A6275ELWTR | 8-bit version of same family, identical SOICW package, same REXT programming and UVLO | Half the channel count - suitable for 8-segment or dual-digit applications, not full 16-bit arrays | Choose when display complexity requires fewer outputs and lower IDD consumption is prioritized |
Compared with TB62706BN and A6275ELWTR, the A6276SLWTR provides full 16-bit drive capability in SOICW with verified UVLO and tighter current matching - making it the only option among the three qualified for new 16-channel LED signage designs operating across –20°C to +85°C.
Availability
A6276SLWTR is available at Aetrix Electronics and suitable for LED signage panels, industrial HMI displays, point-of-sale terminals, and transportation annunciators requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for A6276SLWTR 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, motor drivers, and precision power ICs, headquartered in Worcester, Massachusetts.
The A6276 product line was developed specifically for high-reliability LED-display systems requiring constant-current sinking, serial expandability, and robust thermal performance in compact surface-mount packages.
FAQ
What is the maximum continuous output current per channel for A6276SLWTR at 85°C ambient?
The A6276SLWTR supports up to 90 mA per output continuously at TA = 85°C when VCE = 0.75 V - but this rating applies to the DIP package (RθJA = 50°C/W). For the SOICW package (RθJA = 85°C/W), continuous 90 mA operation requires careful thermal design, including copper pour and airflow, or derating based on actual PD(max) = (150 − TA)/85.
How does the REXT resistor set output current in A6276SLWTR?
In the A6276SLWTR, the external resistor connected to pin 23 (REXT) establishes a reference current that scales all 16 output currents proportionally. With REXT = 250 Ω, typical IO is 75.5 mA at VCE = 0.7 V; with REXT = 470 Ω, typical IO drops to 40.0 mA - enabling precise brightness tuning without per-channel components.
Is A6276SLWTR pin-compatible with A6276ELWTR?
Yes - A6276SLWTR and A6276ELWTR share identical 24-pin SOICW footprints, pin functions, and electrical specifications except for operating temperature range: A6276SLWTR is rated for –20°C to +85°C, while A6276ELWTR extends to –40°C. Both use the same REXT programming and support identical cascade and blanking protocols.
Does A6276SLWTR support daisy-chaining with other A6276 variants?
Yes - the A6276SLWTR features a CMOS SERIAL DATA OUT (pin 22) that is fully compatible with the SERIAL DATA IN of any A6276 variant (A, LW, or LP), enabling seamless daisy-chaining regardless of package type. Signal levels and timing margins meet JEDEC-compliant CMOS thresholds across all variants.
What is the purpose of the undervoltage lockout (UVLO) in A6276SLWTR?
The UVLO circuit in A6276SLWTR disables internal logic and outputs when VDD falls below 3.4 V, preventing undefined shift register states, partial latch updates, and erratic output behavior during power-up/down or brownout events - ensuring clean display initialization and shutdown in the A6276SLWTR.
A6276SLWTR 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):
- 4.5V
- Voltage - Supply (Max):
- 5.5V
- Voltage - Output:
- 4V
- Current - Output / Channel:
- 75.5mA
- Frequency:
- 20MHz
- Dimming:
- -
- Applications:
- -
- Operating Temperature:
- -20°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-SOIC
A6276SLWTR FAQ
1.How can I place an order for A6276SLWTR through Aetrix?
Please submit a Request for Quotation (RFQ) for A6276SLWTR 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 A6276SLWTR reliable?
The price and inventory of A6276SLWTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for A6276SLWTR is usually 5 days.
3.What payment methods are accepted for A6276SLWTR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for A6276SLWTR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for A6276SLWTR?
A6276SLWTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your A6276SLWTR 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 A6276SLWTR?
For technical support, including A6276SLWTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your A6276SLWTR requirements.
6.How does Aetrix verify that A6276SLWTR is sourced from the original manufacturer or authorized distributors?
All A6276SLWTR 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 A6276SLWTR meets industry standards.
7.What is the process for return or replacement of A6276SLWTR?
All A6276SLWTR units undergo pre-shipment inspection (PSI). If there is an issue with A6276SLWTR, 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 A6276SLWTR part is unused and in its original packaging.
Return procedure for A6276SLWTR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
A6276SLWTR Tags
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LYT1604D-TL
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HV9910CLG-G
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CL2N8-G
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BCR420UFD-7
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