Diodes Incorporated AP1084D15L-U

Overview

AP1084D15L-U from Diodes Incorporated is a 5A low-dropout linear regulator in TO252-3L package, delivering fixed 1.5V output with ≤1.4V dropout at full load, ±1.5% initial output tolerance, and integrated thermal shutdown and current limiting. It powers high-speed bus termination and low-current 3.3V logic supplies requiring stable low-voltage regulation from 3V–12V input sources.

For engineers reviewing the AP1084D15L-U datasheet, AP1084D15L-U pinout, AP1084D15L-U application, or AP1084D15L-U equivalent, this page provides verified pin functions, real-world transient response data (≤50mV deviation under 0–5A load step), thermal resistance (θJA = 73°C/W), stability requirements (≥10µF output capacitor, 0.15–20Ω ESR), and validated alternatives for fixed 1.5V LDO replacement in industrial and embedded power rails.

Technical Context

The AP1084D15L-U operates as a fixed-output LDO with internal 1.25V reference and precision resistor divider network setting VOUT = 1.5V. Its control loop maintains regulation with ≤1% load regulation (12–15mV) and 0.2% line regulation across 3V–12V input range at 10mA load.

Thermal protection activates at 150°C junction temperature, and dropout voltage remains ≤1.4V up to 5A output current. The device requires no external compensation and achieves fast transient response via internal frequency compensation optimized for ≥10µF aluminum electrolytic output capacitors.

Key Specifications

Pinout & Package

AP1084D15L-U uses the TO252-3L (DPAK) surface-mount package with exposed thermal tab electrically connected to VOUT. The tab must be soldered to a large copper pour for thermal performance and electrical connection to the output net.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fixed 1.5V LDO applications.

Compared with AP1084T15L-U, the D15L-U saves PCB area and enables automated reflow assembly; versus TLV1117-15CDCY, it delivers 5× output current and 0.2V lower dropout - making it irreplaceable in high-current 1.5V rail generation.

Availability

AP1084D15L-U is available at Aetrix Electronics and suitable for VGA card power delivery, DDR memory termination, industrial PLC I/O modules, and embedded FPGA configuration rails requiring stable component supply with full production traceability.

Supply support for AP1084D15L-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 high-reliability power management, signal integrity, and protection solutions for industrial and computing markets.

The AP1084 product line targets high-current, low-dropout regulation for legacy and cost-sensitive embedded systems - emphasizing thermal robustness, minimal external components, and compatibility with standard aluminum electrolytic capacitors.

FAQ

What is the minimum input voltage required for AP1084D15L-U to regulate at 1.5V output?

The device requires VIN ≥ VOUT + dropout voltage. With maximum dropout of 1.4V at 5A, minimum input is 2.9V. At light loads (<100mA), dropout drops to ~1.3V, allowing operation down to 2.8V. Input below 2.8V causes unregulated output collapse.

Can AP1084D15L-U be used with ceramic output capacitors?

Yes, but only if ESR is ≥0.15Ω. Standard X7R/X5R ceramics have near-zero ESR and may cause instability. Use ESR-specified ceramics (e.g., TDK's C series with 0.2–2Ω ESR) or add a 0.22Ω damping resistor in series with the capacitor to meet stability criteria.

Is the thermal tab of AP1084D15L-U electrically connected to any pin?

Yes - the exposed thermal tab is internally connected to Pin 2 (VOUT). It must be soldered to the same net as the VOUT trace and tied to a large copper pour for both thermal dissipation and electrical continuity. Floating the tab violates safety and thermal specifications.

Does AP1084D15L-U require an input capacitor, and what value is recommended?

Yes - a minimum 10µF aluminum electrolytic capacitor (with 0.15–20Ω ESR) is required between VIN and GND, placed within 5mm of the package. This prevents input voltage sag during 5A load transients and reduces high-frequency noise coupling from upstream switching supplies.