L6221AD

Overview

The L6221AD is a monolithic quad Darlington switch manufactured by STMicroelectronics, designed for high current and high voltage switching applications. It features four non-inverting inputs controlled by a common enable input, with all emitters commoned to the ground pin. The device supports an output voltage up to 50 V and a continuous collector current of 1.8 A per channel. Electrical characteristics include a logic supply voltage range of 4.5 V to 5.5 V, TTL-compatible inputs, and integral fast recirculation diodes. The SO16+2+2 package provides a thermal resistance junction-to-pins of 17 °C/W.

Feature Summary

• Four non-inverting drivers with a common enable control
• TTL-compatible logic inputs for direct connection to logic circuits
• Integral fast recirculation diodes for inductive load switching
• Low saturation voltage for efficient power handling

Applications

• High current, high voltage switching applications
• Solenoid driver circuits
• Inductive device loads requiring fast recirculation

Procurement Notes

Verify the specific ordering suffix against the manufacturer's datasheet to confirm the package type and tape-and-reel configuration. Confirm component status as obsolete or active through official ST channels before procurement planning.

Selection Notes

Select this component when a quad Darlington array with a common emitter configuration is required. Ensure the application operates within the 50 V output voltage limit and 1.8 A continuous collector current rating per channel.

Part Context

The L6221AD belongs to the L6221 family of quad Darlington switches. Other variants include the Power DIP package (E-L6221AS) and obsolete versions such as E-L6221C/CD/CN. The AD designation specifically refers to the SO16+2+2 surface mount package.

Replacement Considerations

Consult the manufacturer's documentation for confirmed substitute part numbers. No public cross-reference data is available in the provided source material.