Diodes Incorporated AP1084DG-13

Overview

AP1084DG-13 from Diodes Incorporated is a 5A low-dropout positive adjustable or fixed-mode linear regulator in TO252-3L package, featuring 1.4V maximum dropout at full load, ±1.5% output voltage accuracy at 3.3V, and built-in thermal shutdown. It delivers stable 3.3V output from 4.8–12V input for high-speed bus termination and low-current logic supplies.

For engineers reviewing the AP1084DG-13 datasheet, AP1084DG-13 pinout, AP1084DG-13 application, or AP1084DG-13 equivalent, key selection considerations include dropout voltage under 5A load, thermal resistance (θJA = 73°C/W), minimum 10µF output capacitance requirement, and fixed 3.3V output configuration confirmed by part suffix "33" in ordering code.

Technical Context

The AP1084DG-13 operates as a three-terminal LDO regulator with internal 1.25V reference and adjustable feedback via external resistors - though this variant is factory-configured for fixed 3.3V output. Its control loop maintains regulation with ≤1.4V VIN–VOUT differential across 0–5A load range and supports fast transient response with <33mV load regulation deviation.

Thermal protection activates at 150°C junction temperature, and stability relies on ≥10µF output capacitor (ESR 0.15–20Ω). The device uses a single NPN pass transistor architecture with current limiting set to 5.1A and minimum load requirement of 10mA.

Key Specifications

Pinout & Package

AP1084DG-13 uses the TO252-3L (DPAK) surface-mount package with exposed thermal tab connected to VOUT. Pin 1 is Adj/GND (ground in fixed mode), Pin 2 is VOUT (also electrically tied to thermal tab), and Pin 3 is VIN. Thermal performance depends on PCB copper area under the tab per Diodes Inc. AP02001 layout guidelines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AP1084KT33G-13 and LD1085V33TR, the AP1084DG-13 offers optimal balance of surface-mount compatibility, lowest thermal resistance among TO252-based 5A LDOs, and tightest guaranteed dropout-making it ideal for space-constrained industrial and computing boards where 3.3V stability under dynamic load is critical.

Availability

AP1084DG-13 is available at Aetrix Electronics and suitable for high-speed bus termination, VGA graphics card power, and low-current 3.3V logic supply applications requiring stable component supply across extended production lifecycles.

Supply support for AP1084DG-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 manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability power management, signal integrity, and protection solutions for industrial, computing, and consumer markets.

The AP1084 series belongs to Diodes' high-current LDO regulator product line, engineered specifically for low-voltage IC supply in high-transient environments such as bus termination and graphics subsystems.

FAQ

Is AP1084DG-13 adjustable or fixed-output?

AP1084DG-13 is a fixed 3.3V output variant. The "33" in the part number denotes factory-trimmed 3.3V regulation; Pin 1 (Adj/GND) is internally grounded, eliminating need for external resistors. Output voltage is guaranteed within ±1.5% over load, line, and temperature.

What is the minimum input voltage required for regulation at 5A load?

The minimum input voltage is 4.7V: VOUT (3.3V) + max dropout (1.4V) = 4.7V. Below this, the device enters dropout and output voltage drops linearly with input. At 5A load and 25°C, typical dropout is 1.3V, allowing operation down to 4.6V with margin.

Can AP1084DG-13 be used without a heatsink?

Yes, for low-duty-cycle or thermally favorable conditions: with θJA = 73°C/W and 2W dissipation (e.g., 12V→3.3V @ 0.23A), junction rise is ~147°C - exceeding 125°C max operating limit. For continuous 5A operation, a heatsink or large copper pour is mandatory to maintain T_J ≤ 125°C.

Does AP1084DG-13 require an input capacitor?

No input capacitor is strictly required for stability, but a ≥1µF ceramic capacitor placed near VIN improves high-frequency noise rejection and mitigates input rail sag during load transients. The datasheet recommends it for robust performance in noisy environments like graphics cards or bus systems.