A6278ELP-T

Overview

The A6278ELP-T is a serial-input constant-current latched LED driver manufactured by Allegro MicroSystems. It features an internal CMOS shift register, data latches, and eight NPN constant-current sink drivers. The device operates with a logic supply voltage ranging from 3.0 V to 5.5 V and supports typical serial data input rates up to 25 MHz. Output drive current is set via a single external resistor, with sinking capabilities reaching up to 90 mA per channel. Key functional parameters include open LED detection signaling through the SERIAL DATA OUT pin, power-on reset (POR), and internal undervoltage lockout (UVLO) alongside thermal shutdown circuitry.

Feature Summary

• Integrates CMOS shift register and latches for direct microprocessor interfacing
• Provides open LED connection detection and signaling capability
• Includes internal protection against undervoltage and excessive temperature

Applications

• LED display systems requiring serial control
• Microprocessor-based lighting control interfaces
• Cascaded LED driver configurations

Procurement Notes

Verify component authenticity and datasheet revision status before integration. Confirm package compatibility with PCB footprint specifications. Check for end-of-life notifications or obsolescence warnings from the manufacturer. Ensure environmental compliance documentation matches project requirements. Validate electrical characteristics against current design constraints.

Selection Notes

Evaluate the 3.0 V to 5.5 V logic supply range against system voltage rails. Assess whether the 25 MHz maximum data rate meets timing requirements. Consider the 90 mA output current limit for load calculations. Verify that the 16-pin eTSSOP-EP package fits mechanical constraints. Review thermal management needs given the integrated shutdown features.

Part Context

This component belongs to the A6278/A6279 family of BiCMOS LED drivers designed for display applications. The A6278 variant specifically provides eight sink channels, whereas the A6279 offers sixteen. Both share identical control logic and interface protocols, differing primarily in channel count and physical package options.

Replacement Considerations

Public confirmed substitute part numbers: MAX6978AUE+, MAX6970AUE+.