STMicroelectronics LD1084V50

Overview

LD1084V50 from STMicroelectronics is a fixed-output 5.0 V, 5 A low-dropout linear voltage regulator in TO-220 package, featuring 1.3 V typical dropout at full load, ±1 % output tolerance at 25 °C, and internal thermal/overcurrent protection for stable power delivery in high-current industrial supplies.

For engineers reviewing the LD1084V50 datasheet, LD1084V50 pinout, LD1084V50 application, or LD1084V50 equivalent, this page delivers verified electrical specs, thermal performance data, fixed-voltage use cases, and direct-fit alternatives with documented parameter differences.

Technical Context

The LD1084V50 uses an NPN pass transistor architecture where quiescent current flows into the load-unlike PNP regulators-improving efficiency and reducing wasted bias current. Its on-chip trimming enables ±1 % initial output accuracy at 25 °C, maintained across –40 °C to +125 °C operating junction temperature.

Dropout voltage remains tightly bounded at ≤1.5 V up to 5 A output current, with line regulation of ≤10 mV (typ.) over VI = 6.6–20 V and load regulation of ≤35 mV (max.) across full load range, supporting stable operation under dynamic input and load conditions.

Key Specifications

Pinout & Package

Supplied in TO-220 package with standard 3-pin through-hole mounting and integral heat sink tab (pin 2). Pin 1 is Input, Pin 2 is Ground (tab), Pin 3 is Output.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fixed-output LDO regulator applications.

Compared with LM2940CT-5.0 and TL783CKTTR, the LD1084V50 uniquely combines 5 A continuous rating, 1.3 V dropout, ±1 % accuracy, and TO-220 pin compatibility-making it the sole choice for high-current, fixed-5V industrial power rails demanding reliability and thermal headroom.

Availability

LD1084V50 is available at Aetrix Electronics and suitable for industrial PLC power supplies, motor drive logic subsystems, and test equipment reference rails requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for LD1084V50 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing silicon solutions for automotive, industrial, and power management applications.

The LD1084xx series was developed as a high-current, low-dropout replacement for legacy 78xx and LM317-based designs-targeting industrial power supplies, motor controls, and instrumentation where thermal efficiency and output precision are critical.

FAQ

What is the minimum input voltage required for stable 5 V output at 5 A?

The LD1084V50 requires a minimum input voltage of 6.3 V to maintain regulation at 5 A, based on its 1.3 V typical dropout voltage. At higher temperatures or worst-case tolerance, design for ≥6.6 V input to ensure margin across –40 °C to +125 °C junction range and ±2 % output variation.

Can LD1084V50 be used in parallel for higher current?

No-LD1084V50 is not designed for parallel operation. Its output voltage tolerance (±1 %) and load regulation (≤35 mV) make current sharing unstable without external ballasting, risking thermal runaway. For >5 A, select a single higher-rated regulator or switch to a DC-DC solution.

Is a heatsink mandatory for continuous 5 A operation?

Yes-a heatsink is mandatory. With R_thJC = 3 °C/W and R_thCA ≈ 47 °C/W (TO-220 in still air), dissipating 6.5 W at 5 A (assuming 1.3 V dropout) raises junction temperature by ~320 °C above ambient-far exceeding 125 °C limit. A 10 °C/W heatsink reduces rise to ~75 °C, enabling safe operation at 25 °C ambient.

Does LD1084V50 require an output capacitor, and what type is recommended?

Yes-minimum 10 µF tantalum or low-ESR aluminum electrolytic capacitor is required for stability. Ceramic capacitors alone are insufficient due to low ESR; if used, add a 1 Ω series resistor to emulate required ESR. Output capacitance directly affects load transient response and ripple suppression.