A6277ELWTR

Overview

The A6277ELWTR is a linear LED driver IC manufactured by Allegro MicroSystems, housed in a 20-SOIC surface-mount package. It features an internal shift register topology with eight independent outputs, each capable of delivering up to 120mA. The device operates on a supply voltage ranging from 4.5V to 5.5V, with a maximum output voltage of 4V. Designed for high-frequency applications, it supports clock frequencies up to 20MHz and includes internal switching capabilities. The component functions within an ambient temperature range of -40°C to 85°C.

Feature Summary

• Integrates an 8-channel linear driver array controlled via a serial shift register interface.
• Supports PWM dimming functionality for precise brightness control of connected loads.
• Includes internal protection mechanisms against thermal overload conditions.

Applications

• General-purpose LED illumination systems
• Industrial indicator lighting arrays
• Consumer electronics display backlights

Procurement Notes

Verify the specific suffix variant (e.g., ELWTR) against official datasheets to confirm RoHS compliance status, as manufacturing updates may alter environmental certifications. Confirm lead times and availability directly with authorized distributors or the manufacturer, as this component is listed as obsolete in several major catalogs. Ensure the selected packaging type matches the intended assembly process requirements.

Selection Notes

Select this component when a low-voltage, multi-channel linear drive solution is required for standard LED arrays. The 20-SOIC package offers a balance between pin count and board space. Consider the 120mA per channel limit and the 5.5V maximum supply voltage when designing power rails. Verify that the application does not require higher current densities or wider input voltage ranges, which would necessitate alternative driver families.

Part Context

The A6277 belongs to Allegro's portfolio of linear LED drivers designed for cost-sensitive applications requiring multiple channels. It utilizes a serial interface to minimize microcontroller GPIO usage. While largely superseded by newer integrated solutions, it remains a reference design for simple, low-power LED matrix driving where linear regulation suffices and complex digital interfaces are unnecessary.

Replacement Considerations

Check for direct pin-compatible successors within the Allegro A62xx series. Evaluate alternative manufacturers offering similar 8-channel linear drivers in SOIC-20 packages if supply chain continuity is critical due to the obsolete status of this specific part number.

FAQ

Does the A6277ELWTR support analog dimming?

No, the device is designed for PWM dimming control via its shift register interface rather than analog current adjustment.

What is the maximum operating frequency for the shift register?

The shift register supports clock frequencies up to 20MHz.