Diodes Incorporated AP1084D50L-U

Overview

AP1084D50L-U from Diodes Incorporated is a 5.0A low-dropout linear regulator in TO252-3L package, delivering fixed 5.0V output with ≤1.4V dropout at full load, ±1% load regulation, and built-in thermal shutdown and current limiting. It powers high-speed bus termination and 3.3V/5V logic supplies in VGA cards and embedded systems requiring stable low-noise DC-DC conversion from 6.5–12V input.

For engineers reviewing the AP1084D50L-U datasheet, AP1084D50L-U pinout, AP1084D50L-U application, or AP1084D50L-U equivalent, this device supports fast transient response, tight output voltage tolerance (4.90–5.10V), and stability with ≥10μF output capacitor-critical for noise-sensitive digital ICs and industrial power rails.

Technical Context

The AP1084D50L-U operates as a fixed-output LDO with internal 1.25V reference and precision error amplifier, enabling regulation down to 1.4V input-to-output differential. Its architecture integrates current-limit protection triggered at 5.1A and thermal shutdown at 150°C junction temperature, ensuring safe operation under overload or poor heatsinking.

Designed for direct replacement of legacy 5V regulators, it requires no external feedback resistors and maintains output stability with aluminum or tantalum capacitors (ESR 0.15–20Ω). The TO252-3L package provides 73°C/W junction-to-ambient thermal resistance under standard PCB layout conditions.

Key Specifications

Pinout & Package

AP1084D50L-U uses the TO252-3L (DPAK) surface-mount package with exposed thermal tab electrically connected to VOUT. The tab must be soldered to a large copper pour for thermal performance and electrical grounding of the output rail.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AP1084K50L-13, the D50L-U offers smaller board area and lower assembly cost; versus LD1085V50, it delivers tighter dropout and lower quiescent current-making it superior for thermally constrained 7–12V fixed-rail applications.

Availability

AP1084D50L-U is available at Aetrix Electronics and suitable for VGA graphics cards, industrial PLC I/O modules, and embedded network switches requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for AP1084D50L-U 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design and manufacturing operations across Asia and the Americas.

The AP1084 series belongs to Diodes' high-current LDO portfolio, engineered specifically for low-voltage, high-current applications including graphics card power, bus termination, and industrial logic supplies-prioritizing dropout voltage, thermal robustness, and transient response.

FAQ

What is the minimum input voltage required for AP1084D50L-U to maintain 5.0V regulation?

The AP1084D50L-U requires VIN ≥ VOUT + 1.4V = 6.4V to regulate at full 5A load. At lighter loads, dropout decreases-e.g., 1.3V at 1A-so 6.3V input sustains regulation across all operating currents. Input below 6.4V risks dropout and output collapse during peak load events.

Can AP1084D50L-U be used in adjustable mode?

No. AP1084D50L-U is factory-trimmed for fixed 5.0V output; its Adj pin is internally grounded. Only part numbers ending in "-U" with blank suffix (e.g., AP1084D-U) support adjustable mode via external R1/R2. Using D50L-U as adjustable would result in undefined or unstable output voltage.

What output capacitor is required for stability?

A minimum 10μF aluminum or tantalum capacitor with ESR between 0.15Ω and 20Ω must be placed directly at the VOUT pin. Ceramic capacitors alone are insufficient due to ultra-low ESR causing phase-margin loss; hybrid or polymer-aluminum types are recommended for best transient response and stability.

Is AP1084D50L-U pin-compatible with older AP1084 variants?

Yes-AP1084D50L-U shares identical TO252-3L pinout and electrical behavior with non-lead-free AP1084D50-U. However, reflow profiles must comply with lead-free soldering standards (peak 260°C), and PCB land patterns should follow Diodes' AP02001 guidelines for thermal reliability.