STMicroelectronics KD1084ADT25R

Overview

KD1084ADT25R from STMicroelectronics is a 2.5 V fixed-output, low-dropout linear voltage regulator delivering up to 5 A output current with ±1 % output voltage tolerance at 25 °C and ±2 % over −40 °C to +125 °C. It features 1.3 V typical dropout at 5 A, 5–10 mA quiescent current, and requires only a 10 µF tantalum output capacitor for stability. It is used in high-current industrial power rails where tight regulation and thermal robustness are required.

For engineers reviewing the KD1084ADT25R datasheet, KD1084ADT25R pinout, KD1084ADT25R application, or KD1084ADT25R equivalent, this page provides verified technical context, package-specific pin functions, real-world application roles, and validated alternative parts for 2.5 V/5 A LDO replacement in embedded power systems.

Technical Context

The KD1084ADT25R implements an NPN-based low-dropout architecture with on-chip trimming for ±1 % initial accuracy at 25 °C. Its dropout voltage remains ≤1.5 V across full load (0–5 A) and temperature (−40 °C to +125 °C), enabling operation with minimal input–output differential.

Quiescent current flows into the load-not wasted as bias-improving efficiency versus PNP regulators. Internal thermal and current limiting protect against overload, while supply voltage rejection exceeds 60 dB at 120 Hz with 25 µF output capacitance.

Key Specifications

Pinout & Package

Supplied in TO-220 package (3-lead, through-hole), with exposed tab electrically connected to Pin 2 (Output) for thermal conduction and mechanical mounting.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 2.5 V/5 A LDO applications.

Compared with LD1085V25, KD1084ADT25R offers ±1 % accuracy and better thermal performance; versus TPS75225KTTR, it delivers full 5 A without derating or external components but with higher dropout-making it optimal for industrial 5 A rails where precision and ruggedness outweigh ultra-low dropout needs.

Availability

KD1084ADT25R is available at Aetrix Electronics and suitable for industrial control systems, FPGA power delivery, automotive body electronics, and test equipment requiring stable component supply with guaranteed long-term availability.

Supply support for KD1084ADT25R 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.

KD1084ADT25R belongs to ST's high-current linear regulator product line, engineered specifically for industrial and automotive power management where reliability, thermal robustness, and precision regulation are critical.

FAQ

What is the maximum input voltage rating for KD1084ADT25R?

The absolute maximum DC input voltage is 12 V, per ST's datasheet Table 2. Operation above this level risks permanent damage. For reliable 2.5 V regulation at 5 A, input must remain ≥3.8 V (2.5 V + 1.3 V dropout) and ≤12 V, with recommended derating for thermal margin at high ambient temperatures.

Can KD1084ADT25R be used in parallel for higher current?

No-KD1084ADT25R lacks built-in current-sharing circuitry or master/slave control. Parallel connection without external ballasting resistors causes unequal current distribution and potential thermal runaway. For >5 A, use a single higher-rated regulator or switch to a controller-based solution.

Is a heatsink mandatory for 5 A operation?

Yes-thermal resistance junction-to-ambient is 50 °C/W in TO-220. At 5 A with 1.3 V dropout, power dissipation is ~6.5 W. Without a heatsink, junction temperature would exceed 125 °C even at 25 °C ambient. A minimum 10 °C/W heatsink is recommended for continuous 5 A operation at 70 °C ambient.

Does KD1084ADT25R require an input capacitor?

While not strictly mandatory for stability, ST recommends ≥10 µF aluminum or tantalum input capacitance close to Pin 1 to suppress source impedance and prevent oscillation during fast load transients. Input ESR should be 0.1–1 Ω; ceramic capacitors alone are insufficient due to ultralow ESR causing instability.