STMicroelectronics LD1084V25

Overview

LD1084V25 from STMicroelectronics is a fixed-output 2.5 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/power limiting for robust operation across –40 °C to +125 °C. It serves as a primary post-regulation stage in industrial power supplies requiring stable low-voltage rails.

For engineers reviewing the LD1084V25 datasheet, LD1084V25 pinout, LD1084V25 application, or LD1084V25 equivalent, this page delivers verified electrical specs, thermal behavior, stability requirements (10 µF min. output capacitor), and real-world design context for high-current 2.5 V systems.

Technical Context

The LD1084V25 uses an NPN-based pass transistor architecture-unlike PNP regulators-so quiescent current flows into the load, improving efficiency at light loads. Its reference voltage is trimmed on-chip to achieve ±1 % initial accuracy at 25 °C.

Dropout voltage remains ≤1.5 V up to 5 A output current, with line regulation of 0.5–6 mV over input range and load regulation of 3–20 mV across full current and temperature range. Supply voltage rejection reaches 60–72 dB at 120 Hz under 5 A load.

Key Specifications

Pinout & Package

Supplied in TO-220 package with standard 3-pin vertical mounting footprint 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, high-current LDO applications.

Compared with LD1084V25, TLV1117-25CDCYR offers smaller footprint but sacrifices 80 % output current and thermal margin; no valid drop-in alternative exists among ST's own portfolio due to its unique 5 A / 2.5 V / TO-220 combination.

Availability

LD1084V25 is available at Aetrix Electronics and suitable for industrial PLC I/O modules, FPGA I/O power delivery, and telecom line card designs requiring stable component supply with guaranteed long-term sourcing.

Supply support for LD1084V25 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 consumer markets since 1987.

The LD1084 series belongs to ST's high-current linear regulator product line, engineered specifically for industrial power systems needing robust, fixed-output LDOs with superior thermal performance and tight DC accuracy.

FAQ

What is the minimum input voltage required for LD1084V25 to maintain regulation at 5 A?

The LD1084V25 requires a minimum input voltage of 3.8 V to sustain 2.5 V output at 5 A, based on its 1.3 V typical dropout voltage. At worst-case 1.5 V dropout (per datasheet), input must be ≥4.0 V. Operation below this threshold causes output collapse and possible thermal stress.

Can LD1084V25 be used without an output capacitor?

No. A minimum 10 µF output capacitor is mandatory for stability per the datasheet. Omitting it risks oscillation, excessive output ripple, and potential device failure under load transients. Tantalum or low-ESR ceramic capacitors are recommended; aluminum electrolytics require careful ESR verification.

Is the TO-220 tab electrically isolated from the circuit ground?

No. The metal tab (Pin 2) is internally connected to ground and serves as both thermal path and electrical reference. It must be mounted to a grounded copper pour or heatsink using insulating hardware only if system isolation is required-and even then, creepage/clearance and thermal derating must be re-evaluated.

How does LD1084V25 handle short-circuit conditions?

The LD1084V25 features internal short-circuit current limiting and thermal shutdown. Under short-circuit, output current is limited to 5.5–6.5 A when VI–VO = 5 V, dropping to 0.5–0.7 A at higher differentials. Junction temperature rise triggers thermal shutdown, which holds until safe cooldown occurs.