A6278ELW-T

Overview

The A6278ELW-T is a serial-input constant-current latched LED driver designed for display applications. It integrates a CMOS shift register, data latches, and eight NPN constant-current sink drivers. The device operates with a logic supply range of 3.0 V to 5.5 V and supports typical serial data input rates up to 25 MHz. Drive current is set by a single external resistor, with outputs capable of sinking up to 90 mA. Key features include open LED detection via the SERIAL DATA OUT pin, Schmitt trigger inputs for noise immunity, and internal UVLO and thermal shutdown circuitry.

Feature Summary

• Integrates an 8-channel constant-current sink array with CMOS shift register and latches for direct microprocessor interfacing.
• Provides open LED connection detection and signaling capability through the dedicated serial data output pin.
• Includes Schmitt trigger inputs to enhance noise immunity and internal protection against under-voltage lockout and thermal overload.

Applications

• LED display systems requiring serial control
• High-density LED matrix driving
• Microprocessor-based lighting control interfaces

Procurement Notes

Verify the specific suffix ELW against the manufacturer datasheet to confirm package type and temperature grade. Ensure the design accounts for the 3.0 V to 5.5 V logic supply requirement and the 25 MHz maximum serial data rate. Confirm that the 90 mA per channel sink current aligns with the target LED specifications and thermal management requirements.

Selection Notes

Select this component when an 8-channel serial interface is required for LED displays. It is suitable for designs needing open-circuit detection and high-speed data shifting. Compare against the A6279 if sixteen channels are necessary. Ensure the application environment stays within the specified operating temperature range and voltage limits.

Part Context

The A6278 belongs to Allegro MicroSystems' family of BiCMOS LED drivers. These devices combine digital logic functions with analog current sinking capabilities. The series is optimized for applications where space efficiency and direct microprocessor connectivity are critical. The A6278 specifically provides eight independent sinks, distinguishing it from other channel counts in the lineup.

Replacement Considerations

The A6279 serves as a functional substitute offering sixteen channels instead of eight. Other variants such as A6278EA-T or A6278ELP-T may offer different packaging options while maintaining identical electrical functionality. Verify pin compatibility before substitution.