STMicroelectronics

L4940D2T5

L4940D2T5 Description

The L4940D2T5 from STMicroelectronics is a fixed-output linear voltage regulator designed to deliver a stable 5V output at up to 1.5A with high efficiency and reliability. Housed in a D2PAK (TO-263) surface-mount package, this regulator is optimized for applications requiring robust power management with minimal dropout voltage (0.9V max at 1.5A). Its wide input voltage range (up to 17V) and advanced protection features make it suitable for demanding industrial, automotive, and consumer electronics applications. Although marked as obsolete, it remains a viable choice for legacy designs due to its proven performance and compliance with ROHS3 and REACH environmental standards.

L4940D2T5 Features

• High Current Output: Supports 1.5A continuous current, ideal for powering medium-load circuits.
• Low Dropout Voltage: 0.9V max at full load, ensuring efficient operation even with marginal input voltage headroom.
• Advanced Protection: Integrates over-temperature, reverse polarity, and short-circuit protection for enhanced system reliability.
• Excellent PSRR: 68dB at 120Hz, minimizing noise and ripple for sensitive analog/digital loads.
• Low Quiescent Current: 8mA typical, reducing power waste in standby modes.
• Wide Operating Range: Accepts input voltages up to 17V, accommodating fluctuating power sources.
• Robust Packaging: D2PAK (TO-263) offers superior thermal dissipation for high-current applications.

L4940D2T5 Applications

• Automotive Systems: Powering ECUs, sensors, and infotainment modules where stable voltage is critical.
• Industrial Controls: Used in PLCs, motor drivers, and instrumentation requiring reliable 5V rails.
• Consumer Electronics: Ideal for set-top boxes, routers, and audio/video equipment.
• Legacy Designs: Suitable for maintaining or upgrading older systems due to its obsolete-but-reliable status.

Conclusion of L4940D2T5

The L4940D2T5 stands out for its high current capability, low dropout, and robust protection features, making it a dependable choice for 5V regulation in harsh environments. While newer alternatives exist, its proven performance, thermal efficiency, and compliance with environmental standards ensure continued relevance in legacy and specialized applications. Engineers seeking a cost-effective, high-performance linear regulator for medium-power systems should consider this device, particularly where durability and noise immunity are priorities.