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Allegro MicroSystems A6275EA-T
- Part No.:
- A6275EA-T
- Manufacturer:
- Allegro MicroSystems
- Category:
- LED Drivers
- Package:
- 16-DIP (0.300", 7.62mm)
- Datasheet:
-
A6275EA-T.pdf
- Description:
- IC LED DRVR LINEAR 75.5MA 16DIP
- Quantity:
- Payment:
- Shipping:
Inventory:1,328
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Product details
Overview
A6275EA-T from Allegro MicroSystems is an 8-bit serial-input constant-current latched LED driver with eight NPN sink outputs, undervoltage lockout, and CMOS shift register/latch logic. It delivers up to 90 mA per output (VCE = 0.7 V, REXT = 250 Ω), supports 20 MHz serial data input at 5 V logic supply, and enables inter-digit blanking via active-low OUTPUT ENABLE. It is used in multiplexed LED displays requiring precise current regulation and microprocessor interface.
For engineers reviewing the A6275EA-T datasheet, A6275EA-T pinout, A6275EA-T application, or A6275EA-T equivalent, key selection considerations include its 16-pin DIP package, –40°C to +85°C operating range, constant-current sink architecture with external REXT programming, and compatibility with cascaded LED driver topologies.
Technical Context
The A6275EA-T integrates a BiCMOS 8-bit serial-to-parallel shift register, independent data latches, and eight matched NPN constant-current sink drivers. Its logic operates from a 4.5–5.5 V VDD supply, with undervoltage lockout triggering below 3.4–4.0 V to prevent erratic operation during power ramp-up.
Each output's current is set by a single external resistor (REXT) connected to pin 15, enabling uniform brightness control across all eight channels. The device supports cascade connections via CMOS SERIAL DATA OUT (pin 14) and allows full output blanking via the active-high LATCH ENABLE and active-low OUTPUT ENABLE pins.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Type | NPN constant-current sink (8 channels) |
| Max Output Current | 90 mA per channel at VCE = 0.7 V, continuous over –40°C to +85°C |
| Logic Supply Voltage | 4.5–5.5 V; enables direct interface with 5 V microcontrollers |
| Serial Data Rate | Up to 20 MHz at VDD = 5 V - supports high-refresh-rate LED displays |
| Undervoltage Lockout | Activates below 3.4–4.0 V - prevents metastable logic states during brownout |
| Thermal Resistance | RθJA = 38 °C/W (DIP package on 4-layer PCB) - defines max power dissipation vs ambient |
| Operating Temperature | –40°C to +85°C (Range E) - qualified for industrial LED signage and instrumentation |
Pinout & Package
Package: 16-pin through-hole DIP (suffix A), lead-free with 100% matte tin plating, JEDEC MS-001 BB compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | GND | Common reference for logic and internal regulator; must be low-impedance to avoid latch-up |
| 2 | SERIAL DATA IN | CMOS input accepting 0–5 V serial bitstream; data shifted on rising clock edge |
| 3 | CLOCK | Rising-edge-triggered shift register clock; min pulse width 50 ns |
| 4 | LATCH ENABLE | Active-high strobe; transfers shift register contents to output latches |
| 5–12 | OUT0–OUT7 | Current-sinking NPN outputs; each sinks up to 90 mA with <0.9 V saturation drop at 85°C |
| 13 | OUTPUT ENABLE | Active-low global blanking control; disables all outputs when high |
| 14 | SERIAL DATA OUT | CMOS-level output for daisy-chaining multiple A6275EA-T devices |
| 15 | REXT | Reference terminal for external current-setting resistor; sets identical IO for all 8 outputs |
| 16 | VDD | 5 V logic supply input; powers shift register, latches, and internal UVLO circuit |
Key Features
| Feature | Design Value |
|---|---|
| 8-channel constant-current sink | Enables uniform LED brightness without per-channel resistors; current set by one REXT |
| Undervoltage lockout (UVLO) | Prevents erroneous data shifting or partial latching during power-up/down transitions |
| CMOS serial interface | Supports direct connection to 5 V microcontrollers with no level-shifting required |
| Daisy-chain capability | SERIAL DATA OUT allows expansion beyond 8 outputs using minimal GPIO resources |
| Inter-digit blanking | Active-low OUTPUT ENABLE provides synchronized global blanking for time-multiplexed displays |
Applications
| LED Matrix Displays | Industrial Panel Meters |
|---|---|
Use Scenario: Driving 8×8 or 8×16 multiplexed LED dot-matrix modules in outdoor signage. IC Role / Device Role / Timing Role: Constant-current sink driver providing synchronized column current control and blanking during row scanning. Use Value: Eliminates brightness variation across LEDs by maintaining ±6.0% output current matching at 40 mA, even with VCE mismatch. | Use Scenario: Illuminating segmented LED indicators on factory-floor HMIs and programmable logic controller interfaces. IC Role / Device Role / Timing Role: Latched LED driver interfacing with 8-bit parallel microcontroller ports via serial shift-in protocol. Use Value: Reduces MCU GPIO count by 8× while supporting 20 MHz update rates - critical for real-time status feedback. |
| Automotive Instrument Clusters | POS Terminal Displays |
Use Scenario: Driving red/green/amber LED segments in analog-style speedometer/tachometer overlays. IC Role / Device Role / Timing Role: High-reliability current sink with UVLO ensuring stable operation during vehicle battery voltage dips. Use Value: Operates down to –40°C and withstands 150°C junction temperature - meets automotive thermal stress requirements. | Use Scenario: Powering multi-digit LED displays in retail point-of-sale terminals with space-constrained PCB layouts. IC Role / Device Role / Timing Role: Through-hole DIP package (A6275EA-T) enables robust manual assembly and rework in low-volume production. Use Value: 16-pin DIP footprint simplifies prototyping and field replacement versus surface-mount alternatives. |
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 |
|---|---|---|---|
| A6279 | Successor device with enhanced open-LED detection, dot correction, and improved thermal performance (RθJA = 32 °C/W). | Designed for new designs requiring fault diagnostics and tighter current matching (±1.5% typical). | Select A6279 for new designs needing diagnostic features and extended lifecycle support; A6275EA-T is Last Time Buy. |
| TB62705CP | Pin-compatible 8-bit LED driver from Toshiba; similar 90 mA output rating but lacks UVLO and has higher IDD(OFF) (2.5 mA vs 1.4 mA typ). | Used in legacy Japanese consumer electronics; requires external UVLO circuitry for brownout immunity. | Choose TB62705CP only for drop-in replacement in existing designs where A6275EA-T is unavailable; verify UVLO absence does not impact system reliability. |
Compared with A6275EA-T, the A6279 offers integrated diagnostics and better thermal efficiency for new designs, while TB62705CP provides mechanical compatibility but requires supplemental brownout protection - making A6275EA-T suitable only for legacy repair or last-time procurement.
Availability
A6275EA-T is available at Aetrix Electronics and suitable for LED matrix displays, industrial panel meters, and automotive instrument clusters requiring stable component supply despite its Last Time Buy status.
Supply support for A6275EA-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 A6275 product line was developed specifically for industrial and commercial LED display systems requiring robust, latch-based constant-current drive with microprocessor serial interface - emphasizing reliability over wide temperature ranges and simplified brightness calibration.
FAQ
What is the maximum continuous output current per channel for the A6275EA-T?
The A6275EA-T delivers up to 90 mA per output channel continuously across the full operating temperature range of –40°C to +85°C, provided VCE ≤ 0.9 V and thermal limits are observed. This rating is confirmed under worst-case conditions with REXT = 250 Ω and applies to all eight outputs simultaneously when mounted on a 4-layer PCB with RθJA = 38 °C/W.
Does the A6275EA-T support daisy-chaining with other LED drivers?
Yes, the A6275EA-T supports daisy-chaining via its CMOS SERIAL DATA OUT (pin 14), which relays shifted data to the next device's SERIAL DATA IN. This enables expansion beyond 8 outputs using a single microcontroller SPI line - a feature confirmed in the functional block diagram and truth table of the A6275EA-T datasheet.
What is the purpose of the REXT pin on the A6275EA-T?
The REXT pin (pin 15) on the A6275EA-T connects to an external resistor that sets the output current for all eight sink drivers identically. With REXT = 250 Ω, typical output current is 75.5 mA per channel at VCE = 0.7 V; changing REXT linearly adjusts current - enabling precise brightness calibration without per-channel components.
Is the A6275EA-T still in active production?
No, the A6275EA-T is classified as Last Time Buy (LTB) with a final order deadline of April 30, 2011. It remains available for existing customer applications but is obsolete for new designs. Allegro recommends transitioning to the A6279 for new projects, as stated in the official substitution notice for the A6275EA-T.
What package type does the A6275EA-T use, and what are its key mechanical features?
The A6275EA-T uses a 16-pin through-hole DIP (Dual In-line Package) with JEDEC MS-001 BB outline. Key features include 2.54 mm pin pitch, 7.62 mm body width, lead-free construction with 100% matte tin plating, and compliance with industrial thermal derating curves up to +85°C ambient - verified in the A6275EA-T thermal characteristics table.
A6275EA-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Allegro MicroSystems
- Series:
- -
- Package/Case:
- 16-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Type:
- Linear
- Topology:
- Shift Register
- Internal Switch(s):
- Yes
- Number of Outputs:
- 8
- Voltage - Supply (Min):
- 4.5V
- Voltage - Supply (Max):
- 5.5V
- Voltage - Output:
- 4V
- Current - Output / Channel:
- 75.5mA
- Frequency:
- 20MHz
- Dimming:
- -
- Applications:
- -
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 16-DIP
A6275EA-T FAQ
1.How can I place an order for A6275EA-T through Aetrix?
Please submit a Request for Quotation (RFQ) for A6275EA-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 A6275EA-T reliable?
The price and inventory of A6275EA-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for A6275EA-T is usually 5 days.
3.What payment methods are accepted for A6275EA-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for A6275EA-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for A6275EA-T?
A6275EA-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your A6275EA-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 A6275EA-T?
For technical support, including A6275EA-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your A6275EA-T requirements.
6.How does Aetrix verify that A6275EA-T is sourced from the original manufacturer or authorized distributors?
All A6275EA-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 A6275EA-T meets industry standards.
7.What is the process for return or replacement of A6275EA-T?
All A6275EA-T units undergo pre-shipment inspection (PSI). If there is an issue with A6275EA-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 A6275EA-T part is unused and in its original packaging.
Return procedure for A6275EA-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
A6275EA-T Tags
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