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Allegro MicroSystems A6275SLW-T
- Part No.:
- A6275SLW-T
- Manufacturer:
- Allegro MicroSystems
- Category:
- LED Drivers
- Package:
- 16-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
A6275SLW-T.pdf
- Description:
- IC LED DRVR LINEAR 75.5MA 16SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,200
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Product details
Overview
A6275SLW-T from Allegro MicroSystems is an 8-bit serial-input constant-current latched LED driver with eight NPN sink outputs, 90 mA max per channel, undervoltage lockout, and CMOS-compatible 5 V logic interface - designed for multiplexed LED displays requiring precise current regulation and microprocessor control.
For engineers reviewing the A6275SLW-T datasheet, A6275SLW-T pinout, A6275SLW-T application, or A6275SLW-T equivalent, key selection criteria include output current programmability via REXT, 10 MHz max clock frequency, active-low OUTPUT ENABLE for inter-digit blanking, and SOICW-16 package thermal performance (RθJA = 48 °C/W).
Technical Context
The A6275SLW-T integrates a serial-to-parallel shift register, independent data latches, and eight matched constant-current sink drivers in a single BiCMOS die. Its architecture enables cascading via SERIAL DATA OUT and supports synchronous latch strobing on LATCH ENABLE high.
Undervoltage lockout activates below 3.4–4.0 V to prevent erratic operation during power ramp-up. Output current is set externally via REXT (e.g., 470 Ω yields 40 mA typ), with ±6.0% matching across outputs at fixed VCE.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | Up to 90 mA per channel, set by external REXT; enables direct drive of high-brightness LEDs without external current-setting resistors per channel. |
| Logic Supply | 4.5–5.5 V; compatible with standard 5 V microcontroller I/O, eliminating level-shifting in most display controller designs. |
| Max Clock Frequency | 10 MHz; supports fast serial loading for high-refresh-rate LED matrices (e.g., ≥1 kHz frame rate with 8-bit data). |
| Output Enable | Active-low INPUT; allows global blanking of all 8 outputs simultaneously for flicker-free multiplexing control. |
| Thermal Resistance | RθJA = 48 °C/W (SOICW); defines maximum continuous power dissipation limit (e.g., 2.2 W at TA = 85°C) before derating required. |
| UVLO Threshold | 3.4–4.0 V; prevents partial functionality during brown-out conditions, ensuring reliable reset behavior at power-on. |
| Propagation Delay | 300–1000 ns (CLOCK/ENABLE/LATCH to OUT); ensures deterministic timing for synchronized LED updates in real-time display systems. |
Pinout & Package
Package: 16-pin SOICW (wide-body surface-mount), lead (Pb)-free, 100% matte tin plating, JEDEC MS-013 AA compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 9, 10 | GND | Common logic and power ground reference; must be low-impedance to avoid noise-induced latch errors. |
| 2 | SERIAL DATA IN | CMOS-level serial input; accepts 5 V logic; data shifted on rising CLOCK edge. |
| 3 | CLOCK | Positive-edge-triggered shift register clock; minimum pulse width 50 ns. |
| 4 | LATCH ENABLE | High-level strobe transfers shift register contents to output latches; enables synchronous update of all 8 outputs. |
| 5–12 | OUT0–OUT7 | Constant-current NPN sink outputs; each delivers up to 90 mA with 0.9 V saturation drop at 85°C. |
| 13 | OUTPUT ENABLE | Active-low global enable; high state disables all outputs (blanking mode) without affecting latch contents. |
| 14 | SERIAL DATA OUT | CMOS-level daisy-chain output; connects to next device's SERIAL DATA IN for expandable LED line driving. |
| 15 | REXT | Current-setting node; external resistor here programs identical sink current for all 8 outputs. |
| 16 | VDD | 5 V logic supply; powers internal CMOS circuitry and bias networks; decoupling capacitor required near pin. |
Key Features
| Feature | Design Value |
|---|---|
| 8-channel constant-current sink | Enables uniform LED brightness across segments without per-channel resistors; reduces BOM count and layout area. |
| Serial cascade capability | Allows expansion beyond 8 outputs using single microcontroller SPI line - e.g., 32-segment display with four A6275SLW-T devices. |
| Inter-digit blanking | Active-low OUTPUT ENABLE permits precise timing control to eliminate crosstalk in multiplexed 7-segment or dot-matrix displays. |
| Undervoltage lockout (UVLO) | Guarantees clean initialization during power-up or brown-out; avoids partial display activation or ghosting. |
| BiCMOS process | Combines low-power CMOS logic with robust bipolar output transistors - achieving 90 mA drive while maintaining 1.4 mA standby current. |
Applications
| 7-Segment Display Driver | Dot-Matrix LED Controller |
|---|---|
Use Scenario: Driving common-anode 7-segment displays in industrial panel meters with 1:8 multiplexing. IC Role / Device Role / Timing Role: Constant-current sink for segment cathodes; handles serial data loading and synchronous latch update under microcontroller SPI control. Use Value: Eliminates 56 discrete current-limiting resistors; maintains consistent segment brightness across temperature (±6.0% output matching). | Use Scenario: Controlling 8×8 monochrome LED matrix in embedded signage with dynamic refresh rates >1 kHz. IC Role / Device Role / Timing Role: Row/column sink driver; uses OUTPUT ENABLE for row blanking and SERIAL DATA OUT for vertical expansion. Use Value: Enables full-frame update in <1 ms using 10 MHz clock; reduces MCU GPIO usage from 16 to 4 lines (CLK, DATA, LATCH, OE). |
| LED Bar Graph Display | Industrial Status Indicator Panel |
Use Scenario: 10-segment bar graph showing analog sensor output (e.g., pressure, voltage) in test equipment. IC Role / Device Role / Timing Role: Current-regulated sink for LED anodes via external common-anode bus; updated via serial command bursts. Use Value: Delivers stable 75.5 mA typical current per LED (REXT = 250 Ω), ensuring visibility under varying ambient light. | Use Scenario: Multi-color status indicators in PLC I/O modules where reliability and long-term calibration stability are critical. IC Role / Device Role / Timing Role: Fault-tolerant LED driver with UVLO protection; operates over –20 to +85°C ambient range (S-grade). Use Value: Maintains specified 90 mA output capability at 85°C junction temperature; eliminates brightness drift due to thermal variation. |
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 16-bit version available; same pinout and functional compatibility. | Supports diagnostic feedback for LED failure detection; required for new designs needing fault reporting. | Select A6279 for new designs - Allegro explicitly recommends it as replacement for A6275SLW-T due to obsolescence status. |
| TB62705CP | Pin-compatible 8-bit LED driver from Toshiba; similar 90 mA output, but lacks UVLO and has higher 2.5 mA standby current. | No built-in undervoltage protection; requires external reset circuitry in low-voltage environments. | Acceptable only for legacy drop-in replacement where UVLO is not required and thermal budget allows higher IDD(OFF). |
Compared with A6275SLW-T, the A6279 offers diagnostic features and lifecycle support for new designs, while TB62705CP provides mechanical compatibility but sacrifices reliability features like UVLO and lower power consumption.
Availability
A6275SLW-T is available at Aetrix Electronics and suitable for industrial HMI panels, legacy LED display upgrades, and repair programs requiring stable component supply despite its Last Time Buy status.
Supply support for A6275SLW-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, motor drivers, and power ICs, headquartered in Worcester, Massachusetts.
The A6275 product line targets cost-sensitive, high-reliability LED display systems requiring integrated constant-current sinking with minimal external components and robust thermal performance.
FAQ
What is the operating temperature range for the A6275SLW-T?
The A6275SLW-T is rated for –20°C to +85°C ambient temperature (S-grade). This range is validated per Allegro's recommended operating conditions and reflects its qualification for industrial display applications where extended thermal stability is required. The SOICW package's RθJA of 48 °C/W supports continuous 90 mA operation within this range when PCB thermal design meets JEDEC 4-layer standards. A6275SLW-T does not support the wider –40°C to +85°C (E-grade) range offered by the DIP variant A6275EA-T.
How is output current set on the A6275SLW-T?
Output current on the A6275SLW-T is set by a single external resistor (REXT) connected between pin 15 (REXT) and ground. For example, a 470 Ω resistor yields 40 mA typical per output (VCE = 0.7 V), while 250 Ω gives 75.5 mA typical. The relationship is inverse and linear per Allegro's GP-061 curve. This design eliminates per-channel resistors and ensures matched current across all eight outputs - a key feature of the A6275SLW-T architecture.
Is the A6275SLW-T pin-compatible with the A6279?
Yes, the A6275SLW-T is pin-compatible with the A6279. Allegro explicitly positions the A6279 as the recommended substitution for existing A6275SLW-T users and new designs. Both share identical SOICW-16 pinout, electrical interface, and functional block diagram. However, the A6279 adds open-LED detection and dot correction - enhancements not present in the A6275SLW-T - making it a functional upgrade rather than a drop-in replacement for diagnostics-critical applications.
Does the A6275SLW-T support daisy-chaining?
Yes, the A6275SLW-T supports daisy-chaining via its CMOS SERIAL DATA OUT (pin 14), which connects directly to the SERIAL DATA IN of the next device. This enables scalable LED driving - for example, three A6275SLW-T devices can drive 24 segments using only one microcontroller SPI data line, clock, latch, and enable signal. The A6275SLW-T's 10 MHz max clock frequency ensures minimal latency in multi-device chains, maintaining real-time update capability.
Why is the A6275SLW-T classified as Last Time Buy?
The A6275SLW-T is classified as Last Time Buy because Allegro MicroSystems discontinued its production as of April 30, 2011, per official documentation. It remains available only for existing customer applications and repair programs - not for new designs. This status reflects end-of-life planning, not performance limitations. Engineers selecting A6275SLW-T must account for finite inventory and plan migration to the A6279, which Allegro confirms as the designated successor with full backward compatibility and enhanced features.
A6275SLW-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Allegro MicroSystems
- Series:
- -
- Package/Case:
- 16-SOIC (0.295", 7.50mm Width)
- 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:
- -20°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SOIC
A6275SLW-T FAQ
1.How can I place an order for A6275SLW-T through Aetrix?
Please submit a Request for Quotation (RFQ) for A6275SLW-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 A6275SLW-T reliable?
The price and inventory of A6275SLW-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for A6275SLW-T is usually 5 days.
3.What payment methods are accepted for A6275SLW-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for A6275SLW-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for A6275SLW-T?
A6275SLW-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your A6275SLW-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 A6275SLW-T?
For technical support, including A6275SLW-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your A6275SLW-T requirements.
6.How does Aetrix verify that A6275SLW-T is sourced from the original manufacturer or authorized distributors?
All A6275SLW-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 A6275SLW-T meets industry standards.
7.What is the process for return or replacement of A6275SLW-T?
All A6275SLW-T units undergo pre-shipment inspection (PSI). If there is an issue with A6275SLW-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 A6275SLW-T part is unused and in its original packaging.
Return procedure for A6275SLW-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
A6275SLW-T Tags
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