Diodes Incorporated AP1117K33G-13

Overview

AP1117K33G-13 from Diodes Incorporated is a 1A low-dropout linear voltage regulator in TO263-3L package, delivering fixed 3.3V output with ≤1.4V dropout at full load, ±1% initial accuracy, and integrated thermal shutdown. It supports input voltages from 4.8V to 18V and is used for stable 3.3V supply in VGA cards, PC peripherals, and high-speed bus termination circuits.

For engineers reviewing the AP1117K33G-13 datasheet, AP1117K33G-13 pinout, AP1117K33G-13 application, or AP1117K33G-13 equivalent, key selection criteria include dropout voltage under 1A load, thermal resistance (θ_JC = 3.5°C/W), fixed 3.3V output tolerance, and TO263-3L thermal pad compatibility with industrial PCB layouts.

Technical Context

The AP1117K33G-13 implements a bandgap-referenced error amplifier driving an NPN pass transistor, enabling fast transient response and stable regulation with ≥10µF output capacitance (ESR 0.15–20Ω). Its internal current limiting and thermal shutdown activate at 150°C junction temperature.

Designed for fixed-output operation, it eliminates external resistor networks-pin 1 is grounded, pin 2 delivers regulated 3.3V, and pin 3 accepts input voltage ≥4.8V. Dropout remains ≤1.4V across 0–125°C operating junction range with ≤33mV load regulation (0–1A).

Key Specifications

Pinout & Package

AP1117K33G-13 uses the TO263-3L (D²PAK) surface-mount package with exposed thermal tab connected to VOUT (pin 2) for enhanced heat dissipation. The 3-pin configuration supports compact layout and high-current routing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MIC29302WU-3.3 and LD1086DT-3.3, AP1117K33G-13 offers optimal balance of low dropout, RoHS-compliant packaging, and TO263-3L thermal performance for cost-sensitive industrial and computing applications where enable functionality is unnecessary.

Availability

AP1117K33G-13 is available at Aetrix Electronics and suitable for VGA graphics cards, PC peripheral interfaces, and industrial bus termination systems requiring stable component supply, consistent parametric performance, and long-term manufacturability.

Supply support for AP1117K33G-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 AP1117 series targets cost-effective, thermally robust linear regulation for legacy and new-design 3.3V/2.5V/1.8V logic rails-designed specifically for high-volume PC, peripheral, and embedded applications demanding proven reliability and drop-in compatibility.

FAQ

What is the maximum input voltage for AP1117K33G-13?

The absolute maximum DC input voltage is 18V, but recommended operating range is 4.8V to 12V for optimal thermal performance and regulation stability. Exceeding 12V increases power dissipation significantly-e.g., at 1A output and 15V input, power loss reaches 11.7W, requiring careful thermal design with the TO263-3L thermal pad.

Does AP1117K33G-13 require an external capacitor on the ADJ pin?

No-AP1117K33G-13 is a fixed 3.3V version; pin 1 (Adj/GND) is internally connected to ground and must be externally tied to system ground. No external resistors or capacitors are needed on this pin, unlike the adjustable AP1117-ADJ variant which uses a resistor divider between VOUT and ADJ.

Can AP1117K33G-13 be used in parallel for higher current?

No-parallel operation is not supported due to mismatched output voltages and lack of current-sharing circuitry. Even minor voltage differences (±1%) cause one device to supply most of the load, risking thermal runaway. For >1A applications, select a single higher-current LDO or switch-mode solution instead.

What is the minimum output capacitance required for stability?

A minimum 10µF tantalum or aluminum electrolytic capacitor (ESR 0.15–20Ω) is required between VOUT and ground. Ceramic capacitors alone are insufficient-low-ESR ceramics (<10mΩ) may cause oscillation unless paired with a series resistor or hybrid approach per Diodes Inc. Application Note AP02001.