Diodes Incorporated AP1117D15L-U

Overview

AP1117D15L-U from Diodes Incorporated is a 1A low-dropout positive fixed-mode linear regulator delivering a precise 1.5V output with ≤1.4V dropout at full load, thermal shutdown protection, and 60–70dB ripple rejection. It uses TO252-3L (DPAK) packaging and targets stable low-voltage supply for 3.3V logic interfaces, VGA card power rails, and PC peripheral voltage translation.

For engineers reviewing the AP1117D15L-U datasheet, AP1117D15L-U pinout, AP1117D15L-U application, or AP1117D15L-U equivalent, key selection criteria include guaranteed 1.5V ±3% output accuracy over 0–125°C, 1.4V max dropout at 1A, thermal shutdown activation at 150°C, and compatibility with 10µF/22µF tantalum or ceramic output capacitors.

Technical Context

The AP1117D15L-U integrates a precision bandgap reference (1.25V typ), error amplifier, and PNP pass transistor in a fixed-output configuration-no external resistors required. Its internal current limiting and thermal foldback ensure safe operation under overload or ambient temperature rise.

Designed for input ranges of 3.0V to 18V, it maintains regulation down to VIN = VOUT + 1.3V and delivers stable 1.5V output with ≤1% load regulation (0–1A) and ≤0.2% line regulation across its operating input range.

Key Specifications

Pinout & Package

AP1117D15L-U is housed in a TO252-3L (DPAK) thermally enhanced surface-mount package with exposed thermal tab electrically connected to VOUT. The tab serves as the primary heat path and must be soldered to a ≥40mm² copper pour for thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AP1117E15L-13, the AP1117D15L-U offers 30% lower thermal resistance (73 vs. 107°C/W), enabling 1A continuous operation on standard FR-4 without heatsink; versus MIC29150-1.5WT, it trades current headroom and ultra-low dropout for guaranteed RoHS compliance and simpler capacitor requirements.

Availability

AP1117D15L-U is available at Aetrix Electronics and suitable for PC peripheral power, VGA card core supply, and embedded logic translation requiring stable component supply, long-term lifecycle support, and lead-free manufacturing compliance.

Supply support for AP1117D15L-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 consumer markets.

The AP1117 series was designed as a pin-compatible family of 1A LDOs targeting cost-sensitive, thermally constrained applications such as PC add-in cards, embedded peripherals, and bus termination networks.

FAQ

What is the minimum input voltage required for AP1117D15L-U to maintain regulation?

The device requires VIN ≥ VOUT + 1.3V to regulate properly, meaning a minimum input of 2.8V. At 1A load, dropout rises to 1.4V, so 2.9V is recommended for margin. Operation below 2.8V causes output collapse and thermal shutdown may activate if sustained.

Can AP1117D15L-U be used with ceramic output capacitors?

Yes, but only if ESR is ≥0.15Ω. Standard X7R/X5R ceramics typically have ESR <0.05Ω and risk instability. Use ESR-stabilized ceramics (e.g., TDK's C Series) or add a 0.22Ω damping resistor in series with the capacitor to meet the 0.15–20Ω ESR requirement.

How does thermal shutdown behave during overload conditions?

When junction temperature reaches ~150°C, the regulator disables output and enters hiccup mode-cycling on/off as the die cools. Recovery occurs automatically once TJ drops below ~135°C. No latch-up or manual reset is needed, but repeated cycling indicates insufficient heatsinking or excessive power dissipation.

Is AP1117D15L-U compatible with lead-free reflow profiles?

Yes. It is RoHS-compliant with lead-free finish and rated for peak reflow temperatures up to 260°C (JEDEC J-STD-020). The TO252-3L package withstands standard Pb-free soldering cycles without delamination or parametric shift, provided preheat and soak times follow Diodes Inc. AP02001 pad layout guidelines.