Diodes Incorporated AP1117E18G-13

Overview

AP1117E18G-13 from Diodes Incorporated is a 1.8V fixed-output, low-dropout linear regulator in SOT223 package delivering up to 1A output current with ≤1.4V dropout at full load, ±1.5% initial output voltage accuracy, and integrated thermal shutdown. It serves as a stable local power supply for 1.8V logic rails in PC peripherals, communication modules, and consumer equipment requiring clean, well-regulated DC voltage from 3.3V–12V input sources.

For engineers reviewing the AP1117E18G-13 datasheet, AP1117E18G-13 pinout, AP1117E18G-13 application, or AP1117E18G-13 equivalent, key selection criteria include dropout voltage under 1A load, thermal resistance (θJA = 107°C/W), output capacitor ESR requirements (<0.5Ω), junction temperature range (−20°C to +125°C), and SOT223 thermal tab connection to VOUT.

Technical Context

The AP1117E18G-13 implements a bandgap-referenced error amplifier driving an NPN pass transistor, enabling fast transient response and stable regulation across line and load variations. Its internal current limiting and thermal shutdown circuitry activate at ≥1.1A and ≥150°C respectively, ensuring robust fault protection without external components.

Designed for fixed 1.8V operation, it eliminates external feedback resistors while maintaining tight load regulation (≤18mV over 0–1A) and line regulation (≤0.2%) - critical for noise-sensitive digital ICs. The SOT223 thermal tab directly connects to VOUT, requiring PCB copper area for effective heat dissipation.

Key Specifications

Pinout & Package

SOT223 package with exposed thermal tab electrically connected to VOUT; requires minimum 5mm × 5mm 2oz copper pad for thermal performance 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 MIC29302WU-1.8 and LD1117S18TR, AP1117E18G-13 offers superior dropout performance (1.4V max) and MLCC compatibility at the cost of narrower industrial temperature rating - making it optimal for cost-sensitive, thermally managed 1.8V logic supplies.

Availability

AP1117E18G-13 is available at Aetrix Electronics and suitable for PC peripheral power, communication module supply, and consumer equipment logic requiring stable component supply with lead-free compliance and SOT223 thermal management capability.

Supply support for AP1117E18G-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 power management, signal integrity, and protection solutions for industrial, computing, and consumer markets.

The AP1117 series targets cost-effective, thermally robust local regulation for logic and interface ICs - emphasizing low dropout, fast transient response, and simplified fixed-voltage implementation in space-constrained designs.

FAQ

What is the minimum input voltage required for AP1117E18G-13 to regulate at 1.8V?

The device requires VIN ≥ VOUT + dropout voltage. With a maximum dropout of 1.4V at 1A, the absolute minimum input is 3.2V. However, Diodes specifies 3.3V minimum input for guaranteed 1.8V regulation at 10mA load per datasheet conditions - allowing margin for line regulation and thermal drift.

Can AP1117E18G-13 operate without an output capacitor?

No. A minimum 4.7µF output capacitor with ESR ≤0.5Ω is mandatory for stability. The device uses this capacitor for internal frequency compensation; omitting it causes oscillation or unregulated output. Ceramic X7R, solid tantalum, or aluminum electrolytic (≥47µF) are acceptable, but Y5V dielectrics are prohibited.

Is the thermal tab of AP1117E18G-13 electrically isolated?

No. The thermal tab is internally connected to the VOUT pin. PCB layout must treat the tab as part of the output net - routing it to the same copper pour as VOUT and its decoupling capacitor. Isolating the tab creates thermal resistance and risks overheating.

Does AP1117E18G-13 support reverse polarity protection?

No. The device lacks internal reverse-battery or reverse-voltage protection. Applying negative voltage to VIN or VOUT relative to GND may damage the IC. External protection diodes or MOSFET-based circuits are required if reverse polarity exposure is possible in the application.