Diodes Incorporated AP1117D50L-U

Overview

AP1117D50L-U from Diodes Incorporated is a 1A low-dropout linear voltage regulator in TO252-3L package, delivering fixed 5.0V output with ≤1.4V dropout at full load, ±2% output voltage accuracy, and integrated thermal shutdown. It serves as a primary post-regulation supply for 3.3V/5V logic rails in PC peripherals and communication modules where input ranges from 6.5V to 12V.

For engineers reviewing the AP1117D50L-U datasheet, AP1117D50L-U pinout, AP1117D50L-U application, or AP1117D50L-U equivalent, key selection criteria include dropout voltage under 1A load, thermal resistance (θ_JA = 73°C/W), ripple rejection (60–70dB at 180Hz), and compatibility with 10µF minimum output capacitance (ESR 0.15–20Ω).

Technical Context

The AP1117D50L-U implements a bandgap-referenced error amplifier driving an NPN pass transistor, enabling stable regulation with fast transient response to load steps. Its internal current limiting and thermal shutdown circuitry activate at ≥1.1A and ≥150°C junction temperature respectively.

Designed for fixed-output operation, it eliminates external feedback resistors-pin 1 is grounded, pin 2 delivers regulated 5.0V, and pin 3 accepts 6.5–12V input. The TO252-3L package's exposed thermal pad (connected to VOUT) enables efficient heat dissipation up to 15W under proper PCB layout.

Key Specifications

Pinout & Package

AP1117D50L-U uses the TO252-3L (DPak) surface-mount package with exposed thermal tab electrically connected to VOUT (pin 2). The tab must be soldered to a ≥400mm² copper pour for thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MIC29302WU-5.0 and LD1117S50TR, AP1117D50L-U offers optimal balance of thermal capability (73°C/W), proven 1A continuous operation in TO252, and industry-standard 5V fixed output-making it ideal for thermally demanding, medium-power embedded applications without redesigning layout or recalculating thermal margins.

Availability

AP1117D50L-U is available at Aetrix Electronics and suitable for PC peripheral power, communication module supply, VGA card logic, and embedded controller rail applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant manufacturing.

Supply support for AP1117D50L-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 power management, signal integrity, and protection solutions for industrial, computing, and communications markets.

The AP1117 series belongs to Diodes' precision linear regulator product line, engineered specifically for low-noise, high-stability post-regulation in space-constrained, thermally challenging environments like add-in cards and network edge devices.

FAQ

What is the minimum input voltage required for AP1117D50L-U to regulate 5.0V output?

The device requires VIN ≥ VOUT + 1.3V to maintain regulation, so minimum input is 6.3V. At 1A load, dropout rises to 1.4V, making 6.4V the practical minimum for guaranteed performance across temperature and process variation. Operation below this risks output sag or dropout.

Can AP1117D50L-U be used with ceramic output capacitors?

Yes, but only with careful ESR consideration: the datasheet specifies 0.15–20Ω ESR for stability. Standard X7R/X5R ceramics have near-zero ESR and may cause oscillation. Use ESR-specified ceramics (e.g., "low-ESR" types) or add a 1–2Ω damping resistor in series with the capacitor if using standard MLCCs.

How does thermal shutdown behave during sustained overload?

When junction temperature reaches ~150°C, the regulator disables output and enters thermal shutdown. It remains off until die cools to ~135°C, then resumes regulation. This hiccup-mode cycling protects against permanent damage but causes output interruption-designers must size heatsink or reduce load to avoid repeated cycling.

Is AP1117D50L-U compatible with lead-free reflow profiles?

Yes-the TO252-3L package and "L" suffix confirm lead-free termination and RoHS compliance. It supports standard JEDEC J-STD-020D reflow profiles with peak temperature up to 260°C. Ensure PCB pad layout follows Diodes' AP02001 guidelines for thermal reliability and solder joint integrity.