Diodes Incorporated AP1184K5-50L-U

Overview

AP1184K5-50L-U from Diodes Incorporated is a 4A ultra-low dropout positive fixed-mode linear regulator in TO263-5L package, delivering precisely regulated 5.0V ±3% output with 0.85V max dropout at 4A load, thermal shutdown, and remote sensing via Vsense pin. It targets GPU core power delivery from 3.3V/5V ATX rails in graphics card designs requiring fast transient response and tight voltage tolerance.

For engineers reviewing the AP1184K5-50L-U datasheet, AP1184K5-50L-U pinout, AP1184K5-50L-U application, or AP1184K5-50L-U equivalent, key selection criteria include dropout voltage under full load, remote sense capability for load-point regulation, thermal resistance (θJC = 7°C/W), control pin (Vctrl) biasing requirements, and compatibility with aluminum electrolytic output capacitors ≥100µF.

Technical Context

The AP1184K5-50L-U uses an NPN pass transistor architecture with externally biased Vctrl pin-enabling lower dropout than standard PNP LDOs while avoiding base current losses. Its dedicated Vsense pin enables true Kelvin sensing, compensating for PCB trace IR drop between regulator and load.

It integrates current limiting (4.2A min), thermal shutdown (TJ > 150°C), and achieves 70dB ripple rejection at 120Hz. The fixed 5.0V output eliminates external resistor networks, simplifying layout versus adjustable variants while retaining fast transient response (<500ns load step).

Key Specifications

Pinout & Package

AP1184K5-50L-U is housed in a surface-mount TO263-5L (D²PAK) package with exposed copper thermal pad (Vout-connected). The tab serves as both thermal path and electrical connection to Vout.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A8300RGRT and MCP1826-5002E/DB, AP1184K5-50L-U uniquely combines 4A capability, true remote sensing, and ultra-low dropout in a single TO263-5L package-making it irreplaceable for GPU core supply where load-point regulation and thermal headroom are non-negotiable.

Availability

AP1184K5-50L-U is available at Aetrix Electronics and suitable for graphics card manufacturing, FPGA-based industrial controllers, medical imaging sensor modules, and precision test equipment requiring stable component supply with full traceability and lifecycle continuity.

Supply support for AP1184K5-50L-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 semiconductor manufacturer specializing in discrete, analog, and mixed-signal ICs, with emphasis on power management, signal integrity, and protection solutions.

The AP1184 series belongs to Diodes' high-current LDO portfolio, engineered specifically for graphics processor and FPGA power delivery where ultra-low dropout, remote sensing, and thermal resilience are mandatory.

FAQ

What is the minimum input voltage required for AP1184K5-50L-U to regulate 5.0V at 4A?

The absolute minimum input voltage is 5.85V-calculated as Vout + max dropout (5.0V + 0.85V). However, design margin requires ≥6.0V to ensure regulation across temperature, line, and load variations. Input must also exceed Vctrl (≥6.0V) since Vctrl must be ≥1V above Vout.

Can AP1184K5-50L-U be used without remote sensing?

Yes-Vsense can be shorted directly to Vout for local regulation. However, this forfeits the primary advantage of the device: load-point accuracy. Without remote sensing, PCB trace resistance introduces up to ±25mV error per 6mΩ of trace impedance at 4A, degrading GPU voltage margin.

Why does Vctrl require a separate ≥100µF capacitor?

Vctrl powers the internal control circuitry and base drive for the NPN pass transistor. Its capacitor stabilizes the bias network during large load transients; undersizing causes oscillation or dropout. The 100µF value ensures sufficient charge reservoir to maintain Vctrl ≥1V above Vout during 4A steps with <100ns rise time.

Is AP1184K5-50L-U recommended for new designs?

No-Diodes Incorporated explicitly marks AP1184 as "NOT RECOMMENDED FOR NEW DESIGN" in its datasheet (Rev. 6-3, Oct 2014). It remains supported for legacy production and repair, but newer alternatives like AP7361D or AP7363 offer improved PSRR, lower quiescent current, and active lifecycle status.