STMicroelectronics KD1084DT25R

Overview

KD1084DT25R from STMicroelectronics is a fixed-output 2.5 V, ±2% tolerance, low-dropout linear voltage regulator delivering up to 5 A output current in DPAK package. It features 1.3 V typical dropout at full load, −40 °C to +125 °C operating junction temperature range, and requires only a 10 µF output capacitor for stability. It is used in high-current industrial power rails where tight thermal margin and minimal input–output differential are critical.

For engineers reviewing the KD1084DT25R datasheet, KD1084DT25R pinout, KD1084DT25R application, or KD1084DT25R equivalent, this page provides verified electrical specs, thermal performance data, real-world load/line regulation behavior, and validated drop-in alternatives for 2.5 V system rail design.

Technical Context

The KD1084DT25R implements an NPN-based low-dropout architecture with on-chip trimming for output accuracy, enabling stable 2.5 V regulation across 0–5 A load while maintaining 1.3–1.5 V dropout. Its quiescent current flows into the load-not wasted as bias-improving efficiency versus PNP regulators.

It integrates internal thermal shutdown and current limiting, supports input voltages up to 12 V DC, and achieves 60–72 dB supply voltage rejection at 120 Hz with 25 µF output capacitance. Output noise is specified at 0.003 % RMS of VO (10 Hz–10 kHz).

Key Specifications

Pinout & Package

Supplied in surface-mount DPAK (TO-252) package with exposed thermal pad for enhanced heat dissipation. Pin 1 = Input, Pin 2 = Ground, Pin 3 = Output.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LD1085V25 and TLV1117-25, KD1084DT25R uniquely delivers 5 A at ±2 % over full temperature range in DPAK, making it the only direct-fit solution for thermally constrained, high-current 2.5 V rails requiring guaranteed accuracy without derating.

Availability

KD1084DT25R is available at Aetrix Electronics and suitable for industrial motor control, telecom base station power, and automotive infotainment systems requiring stable component supply with long lifecycle visibility.

Supply support for KD1084DT25R 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 microcontrollers, power management ICs, and analog components for industrial, automotive, and consumer markets.

KD1084DT25R belongs to ST's high-current LDO regulator product line, engineered specifically for applications demanding >3 A output with low dropout, wide temperature operation, and minimal external components.

FAQ

What is the minimum input voltage required for KD1084DT25R to regulate at 5 A?

The datasheet specifies a maximum dropout voltage of 1.5 V at 5 A. To maintain 2.5 V output, the minimum input voltage is therefore 4.0 V. At lower loads, dropout decreases - e.g., 1.3 V typical at 5 A means 3.8 V input suffices under nominal conditions. Input must remain ≥4.1 V across all operating temperatures per Table 8.

Can KD1084DT25R be used with ceramic output capacitors?

Yes, but only if a minimum 10 µF ceramic capacitor with ≥5 mΩ ESR is used, or a 10 µF ceramic in parallel with a 1–2 Ω damping resistor. The original design targets tantalum (low ESR), and ceramic-only use may cause instability unless phase margin is verified via load-step testing or SPICE simulation with accurate capacitor model.

Does KD1084DT25R require an input bypass capacitor?

Yes - a minimum 10 µF input capacitor (tantalum or aluminum electrolytic) is recommended within 10 mm of the IN pin to limit peak input current and suppress high-frequency noise from upstream supplies. Without it, line transient response degrades and PSRR drops above 10 kHz, risking coupling into sensitive downstream circuits.

How does thermal performance differ between DPAK and TO-220 packages for KD1084DT25R?

DPAK has R_thJA = 100 °C/W vs. TO-220's 50 °C/W - meaning DPAK requires nearly twice the PCB copper area for equivalent thermal rise. However, DPAK offers superior solder-joint reliability in reflow assembly and smaller footprint. For 5 A continuous operation at 70 °C ambient, TO-220 can use minimal heatsink while DPAK needs ≥4 cm² 2-oz copper with thermal vias to stay below 125 °C junction.