Diodes Incorporated AP1084K33L-13

Overview

AP1084K33L-13 from Diodes Incorporated is a 5A low-dropout linear regulator in TO263-3L package, fixed 3.3V output, with 1.4V max dropout at full load, thermal shutdown, and current limiting. It delivers stable 3.3V/5A power for high-speed bus termination, VGA card logic supplies, and industrial embedded systems requiring tight regulation under fast load transients.

For engineers reviewing the AP1084K33L-13 datasheet, AP1084K33L-13 pinout, AP1084K33L-13 application, or AP1084K33L-13 equivalent, key selection criteria include dropout voltage at 5A, thermal resistance (θJC = 3.5°C/W), output stability with ≥10µF/0.15–20Ω ESR capacitor, fixed 3.3V accuracy (±2% over line/load/temp), and TO263-3L thermal tab mounting requirements.

Technical Context

The AP1084K33L-13 integrates a precision 1.25V reference, error amplifier, and NPN pass transistor in a fixed-output configuration-no external resistors required. Its internal current limit (5.1A min) and thermal shutdown (150°C trip) operate independently of external components.

Designed for input ranges of 4.8V–12V, it maintains regulation with only 1.4V headroom at 5A, enabling efficient 3.3V generation from 5V or 12V rails. Fast transient response and <1% load regulation (26–33mV) support dynamic loads typical in graphics and memory subsystems.

Key Specifications

Pinout & Package

AP1084K33L-13 uses the TO263-3L (D²PAK) thermally enhanced surface-mount package with exposed metal tab electrically connected to VOUT. The tab must be soldered to a large PCB copper area for thermal conduction and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AP1084T33L-U and LD1085V33, AP1084K33L-13 offers superior thermal performance (θJC = 3.5°C/W vs 3.5°C/W for TO220 but better PCB heat spreading in TO263) and full 5A capability in a compact surface-mount footprint-critical for high-density graphics and embedded controller designs where space and thermal management are co-constrained.

Availability

AP1084K33L-13 is available at Aetrix Electronics and suitable for PCI Express graphics power, VGA card logic supplies, and industrial I/O module design requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for AP1084K33L-13 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 semiconductor company specializing in discrete, analog, and mixed-signal ICs for power management, signal integrity, and connectivity applications.

AP1084 belongs to Diodes' high-current LDO regulator product line, engineered specifically for low-voltage, high-current IC supply applications including graphics subsystems, bus termination, and industrial logic rails where dropout voltage and thermal performance are critical.

FAQ

What is the minimum input voltage required for AP1084K33L-13 to regulate at full 5A load?

The device requires VIN ≥ VOUT + 1.4V = 4.7V minimum to maintain regulation at 5A. At 4.8V input, it delivers full 3.3V/5A with ≤1% deviation; below 4.7V, output collapses into dropout. Input must also stay within absolute max rating of 12V.

Can AP1084K33L-13 be used in adjustable mode?

No. The "33" suffix denotes factory-trimmed fixed 3.3V output; the Adj pin is internally grounded and not functional for external programming. Only adjustable versions (e.g., AP1084K-13) support external resistor feedback.

Is a heatsink required for AP1084K33L-13 operating at 5A continuous?

Yes - the TO263-3L package requires direct thermal pad soldering to ≥4 cm² of 2oz copper on the PCB. Without adequate copper area, junction temperature exceeds 150°C at 5A with 5V input (15W dissipation). No external heatsink is needed if PCB copper meets Diodes' AP02001 layout guidelines.

What output capacitor specifications ensure stability for AP1084K33L-13?

A minimum 10µF aluminum or polymer capacitor with ESR between 0.15Ω and 20Ω is required. Tantalum capacitors are acceptable but must meet ESR range; ceramic capacitors alone are insufficient due to near-zero ESR causing instability. Place capacitor within 5mm of VOUT and GND pins.