Diodes Incorporated AP1084T50L-U

Overview

AP1084T50L-U from Diodes Incorporated is a 5A low-dropout positive fixed-mode voltage regulator delivering a precise 5.0V output with ≤1.4V dropout at full load, thermal shutdown protection, and ±1% load regulation (40–50mV) across 0–5A. It uses TO220-3L packaging with tab-connected VOUT and supports high-speed bus termination and 3.3V/5V logic supply in VGA cards and embedded power rails.

For engineers reviewing the AP1084T50L-U datasheet, AP1084T50L-U pinout, AP1084T50L-U application, or AP1084T50L-U equivalent, key selection criteria include dropout voltage under 5A load, thermal resistance (θJA = 78°C/W), fixed 5.0V output tolerance (±1%), minimum 10µF output capacitance requirement, and TO220-3L thermal tab mounting for heatsink integration.

Technical Context

The AP1084T50L-U implements a three-terminal LDO architecture with internal 1.25V reference and current-limiting circuitry. Its fixed 5.0V output is achieved by internal resistor network-no external adjust components required-enabling simplified layout versus adjustable variants.

It features fast transient response (≤100µs recovery from 0→5A step), built-in thermal shutdown at 150°C junction temperature, and guaranteed stability with ≥10µF output capacitor (ESR 0.15–20Ω). Input voltage range is 6.5–12V for 5.0V operation, requiring ≥1.4V headroom above VOUT to maintain regulation.

Key Specifications

Pinout & Package

AP1084T50L-U uses TO220-3L package with exposed thermal tab electrically connected to VOUT (Pin 2). Mounting requires isolation from chassis ground unless VOUT is system ground; tab must be thermally coupled to heatsink via thermal compound or pad.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AP1084T50G-U, the AP1084T50L-U offers identical regulation and protection but differs in molding compound chemistry; versus TLV1117-50, it delivers 6.25× more current, superior thermal robustness, and full-system protection-making it irreplaceable in high-power industrial LDO roles.

Availability

AP1084T50L-U is available at Aetrix Electronics and suitable for VGA graphics card power, industrial PLC I/O modules, and embedded media processor core rails requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant through-hole packaging.

Supply support for AP1084T50L-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, specializing in high-reliability power management, signal integrity, and protection devices for industrial, computing, and consumer markets.

The AP1084 series belongs to Diodes' high-current LDO portfolio, designed specifically for low-voltage IC supply in high-speed bus termination, graphics subsystems, and legacy-compatible 5V logic rails where thermal resilience and dropout efficiency are critical.

FAQ

Can AP1084T50L-U be used in adjustable mode?

No. The "50" suffix denotes fixed 5.0V output; internal resistor network replaces the external adjust pin function. Pin 1 (Adj/GND) is internally grounded and must be externally connected to system ground-no external resistors can alter output voltage. Attempting adjustment will result in incorrect regulation or instability.

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

The minimum input voltage is 6.5V, per datasheet conditions for 5.0V operation. This ensures ≥1.4V headroom above VOUT (5.0V + 1.4V = 6.4V), accounting for worst-case dropout. Below 6.5V, regulation fails and output drops linearly with input; operation below 6.5V is not guaranteed.

Is a heatsink mandatory for 5A continuous operation?

Yes. With θJA = 78°C/W and P_D ≈ 7.5W (at V_IN = 7V), junction temperature rises ~585°C above ambient without heatsinking-far exceeding 150°C limit. A heatsink reducing θ_JA to ≤20°C/W is required to maintain T_J ≤125°C at 5A in 25°C ambient.

Does AP1084T50L-U require an input capacitor?

Yes. A 100µF aluminum or tantalum capacitor is recommended at VIN to suppress input impedance spikes during load transients. Without it, line transient response degrades significantly-observed overshoot exceeds ±150mV in typical 5A step tests per datasheet Figure 6.