Diodes Incorporated AP1117E15L-13

Overview

AP1117E15L-13 from Diodes Incorporated is a 1.5V fixed-output, 1A low-dropout linear regulator in SOT223 package, designed for stable voltage regulation in space-constrained applications requiring precise 1.5V supply-such as DDR memory termination, FPGA core logic, and embedded microcontroller I/O rails. It guarantees ≤1.4V dropout at full 1A load, operates with 3V to 12V input, and maintains ±1.5% output accuracy over 0°C to +125°C junction temperature.

For engineers reviewing the AP1117E15L-13 datasheet, AP1117E15L-13 pinout, AP1117E15L-13 application, or AP1117E15L-13 equivalent, key selection criteria include dropout voltage at 1A, thermal shutdown behavior, SOT223 thermal resistance (θJA = 107°C/W), output capacitor ESR requirements (<0.5Ω), and fixed 1.5V output tolerance under load/line transients.

Technical Context

The AP1117E15L-13 integrates a precision bandgap reference, error amplifier, current-limit protection, and thermal shutdown circuitry in a monolithic IC. Its internal architecture delivers fast transient response to load steps up to 1A, with ripple rejection of 60–70dB at 180Hz using a 25µF tantalum output capacitor.

It functions as a three-terminal fixed-mode regulator: VIN (Pin 3), VOUT (Pin 2, also connected to thermal tab), and GND (Pin 1). Stability is ensured with ≥4.7µF ceramic (X7R) or solid tantalum output capacitance and matching input decoupling, both with ESR ≤0.5Ω and trace length ≤10mm.

Key Specifications

Pinout & Package

SOT223-3 package: surface-mount, thermally enhanced with exposed metal tab tied to VOUT (Pin 2) for PCB heat sinking. Dimensions: 6.50 × 3.50 × 1.60 mm (L × W × H), 5mm × 5mm copper pad recommended for θJA = 107°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MIC29150-1.5WT and LD1117S15TR, AP1117E15L-13 offers optimal balance of industrial temperature range, SOT223 footprint, and 1.4V dropout-making it preferred for compact, wide-temperature embedded systems where thermal design margin is constrained.

Availability

AP1117E15L-13 is available at Aetrix Electronics and suitable for DDR memory termination, FPGA I/O supply, and microcontroller core logic applications requiring stable component supply, long-term manufacturability, and RoHS-compliant packaging.

Supply support for AP1117E15L-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 belongs to Diodes' precision LDO regulator product line, engineered specifically for low-noise, low-dropout voltage regulation in space- and thermal-constrained digital systems-including memory interfaces, FPGA power, and MCU subsystems.

FAQ

What is the minimum input voltage required for AP1117E15L-13 to regulate 1.5V output?

The device requires VIN ≥ VOUT + dropout voltage. With a maximum dropout of 1.4V at 1A, the absolute minimum input is 2.9V. For reliable operation across temperature and load, Diodes recommends VIN ≥ 3.0V-verified by datasheet test conditions specifying 3V input for 1.5V output testing at 10mA.

Can AP1117E15L-13 be used with ceramic capacitors, and what ESR is required?

Yes-it is explicitly qualified for MLCC (X7R dielectric) output capacitors. The datasheet mandates ESR ≤0.5Ω and minimum 4.7µF capacitance. Y5V ceramics are prohibited due to voltage/temperature coefficient instability; X7R is required for guaranteed stability and transient performance.

Is the thermal tab of AP1117E15L-13 electrically connected, and how must it be handled on the PCB?

Yes-the SOT223 thermal tab is internally bonded to Pin 2 (VOUT). It must be soldered to a dedicated copper pour connected to the 1.5V output net-not to ground. This provides both thermal conduction (θJC = 15°C/W) and electrical continuity; floating or grounding the tab causes regulation failure and thermal runaway.

Does AP1117E15L-13 support reverse polarity or reverse current protection?

No-it lacks integrated reverse-voltage or reverse-current blocking. If input can fall below output (e.g., during power-down), an external Schottky diode between VIN and VOUT is required to prevent backfeed and potential damage. This limitation is documented in the Absolute Maximum Ratings section (VIN must always be ≥ VOUT + 1.3V).