Diodes Incorporated AP1186K5-18G-13

Overview

AP1186K5-18G-13 from Diodes Incorporated is a 1.5A ultra-low dropout positive fixed-mode linear regulator with 1.8V output, TO263-5L package, 0.38V max dropout at 1.5A, and integrated thermal shutdown and current limiting. It delivers stable 1.8V supply for graphics chipset core voltage regulation from 3.3V ATX rails.

For engineers reviewing the AP1186K5-18G-13 datasheet, AP1186K5-18G-13 pinout, AP1186K5-18G-13 application, or AP1186K5-18G-13 equivalent, key selection criteria include dropout voltage under full load, remote sensing capability via Vsense pin, thermal resistance (2.5°C/W junction-to-case), control pin (Vctrl) biasing requirements, and stability with ≥100µF aluminum electrolytic output capacitance.

Technical Context

The AP1186K5-18G-13 uses an NPN pass transistor architecture with externally biased Vctrl pin-enabling lower dropout than standard PNP LDOs while avoiding base current losses. Its 5-pin configuration separates Vout and Vsense to support true remote sensing for ±1% load regulation across PCB trace resistance.

It operates with Vctrl ≥ Vin + 1V and requires minimum 100µF output capacitance with 50–100mΩ ESR for loop stability. The device maintains 1.8V output with ±2% tolerance over 0–150°C junction temperature and 0–1.5A load, with 70dB ripple rejection at 120Hz.

Key Specifications

Pinout & Package

AP1186K5-18G-13 is housed in a surface-mount TO263-5L (D²PAK) package with exposed tab electrically connected to Vout for thermal conduction. The tab must be soldered to ≥1.4"×1.4" copper pour for rated 1.5A operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AP1186T5-18G-13, the K5 variant offers identical regulation performance in a smaller surface-mount footprint; versus TPS7A4700RGWR, it trades lower noise for essential remote sensing and higher dropout tolerance-critical for graphics and FPGA applications with distributed loads.

Availability

AP1186K5-18G-13 is available at Aetrix Electronics and suitable for GPU core power supplies, FPGA I/O banks, and industrial camera sensor biasing requiring stable component supply, RoHS-compliant packaging, and long-lifecycle availability.

Supply support for AP1186K5-18G-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 power management, signal integrity, and protection solutions for industrial, computing, and consumer markets.

The AP1186 product line targets high-current, ultra-low-dropout linear regulation for graphics, FPGA, and ASIC core supplies-designed specifically to replace inefficient PNP-based regulators while maintaining simplicity and cost-effectiveness.

FAQ

What is the minimum output capacitance required for stable operation?

The AP1186K5-18G-13 requires a minimum of 100µF aluminum electrolytic capacitor at the Vout pin with 50–100mΩ ESR for guaranteed stability and optimal transient response. This value ensures proper frequency compensation and prevents oscillation under full 1.5A load conditions, as validated in Diodes' application note AP02001.

Can the Vsense pin be left unconnected in local regulation mode?

No. The Vsense pin must be connected directly to the Vout pin (or to the load) in all configurations-even for local regulation-to complete the internal feedback loop. Leaving it floating causes regulation failure and potential overvoltage. For local use, tie Vsense to Vout with a short, low-inductance trace.

What happens if the Vctrl voltage falls below Vin + 1V?

If Vctrl drops below Vin + 1V, the internal control circuitry cannot properly bias the NPN pass transistor, resulting in loss of regulation, increased dropout, and possible output collapse under load. Diodes specifies Vctrl ≥ Vin + 1V across the full operating temperature range to ensure reliable 1.8V output at 1.5A.

Is AP1186K5-18G-13 qualified for automotive applications?

The AP1186K5-18G-13 is not AEC-Q100 qualified. While it operates from 0°C to +150°C junction temperature and includes thermal shutdown, Diodes does not list it in their automotive-grade product portfolio. For automotive infotainment SoC core supplies, consult Diodes' AEC-Q100-certified AP73xx or AP220xx series instead.