LD1084V50

Overview

The LD1084V50 is a fixed-output low-dropout positive voltage regulator manufactured by STMicroelectronics. It provides a guaranteed output current of up to 5 A with a typical dropout voltage of 1.3 V at full load, and a maximum dropout of 1.5 V. The device delivers a fixed 5.0 V output with an accuracy of ±1% at 25°C and ±2% across the full temperature range. It operates within an input voltage range of 6.6 V to 30 V and supports junction temperatures from -40°C to +125°C. Internal protections include thermal limiting and short-circuit current limiting.

Feature Summary

• Pin-to-pin compatible with standard adjustable three-terminal regulators while offering improved dropout performance and tighter output tolerance.
• Quiescent current flows into the load rather than being wasted, increasing overall system efficiency compared to PNP-based regulators.
• Requires only a minimum 10 µF capacitor for stability, simplifying external component requirements.

Applications

• SCSI-2 active termination circuits
• General-purpose power supply regulation
• Battery-powered systems requiring high efficiency

Procurement Notes

Verify the specific order code (LD1084V50) against the manufacturer's official documentation to ensure correct package type and revision level. Confirm that the application environment remains within the specified absolute maximum ratings, particularly regarding input voltage limits and thermal dissipation capabilities in the TO-220 package.

Selection Notes

Select this component when a fixed 5 V output is required with high current capability up to 5 A. It is suitable for designs needing tight voltage tolerance and efficient operation where quiescent current consumption impacts battery life. Ensure adequate heat sinking is provided given the thermal resistance characteristics of the TO-220 package under heavy loads.

Part Context

The LD1084V50 belongs to the LD1084xx family of 5 A low-dropout positive voltage regulators. This series includes both adjustable and fixed output versions (2.5 V, 5 V, 12 V). The device utilizes on-chip trimming to achieve precise output voltage regulation and integrates internal protection mechanisms to safeguard against thermal overload and short circuits.

Replacement Considerations

The datasheet notes pinout compatibility with older standard adjustable VREGs. However, no specific substitute part numbers are documented in the provided source material.

FAQ

What is the minimum capacitance required for stability?

A minimum of 10 µF is required for stability.

How does the quiescent current behavior differ from PNP regulators?

Unlike PNP regulators where quiescent current is wasted, the LD1084V50 directs quiescent current into the load, thereby increasing efficiency.