Diodes Incorporated AP2181WG-7

Overview

AP2181WG-7 from Diodes Incorporated is a single-channel, active-low high-side USB power switch optimized for hot-swap and USB 2.0-compliant applications. It delivers 1.5A continuous load current with 95mΩ typical R_DS(ON), 2.1A accurate current limiting, reverse current blocking, and integrated 7ms deglitch on the open-drain FLG output. Used in laptop USB ports and docking stations to prevent inrush surges and report over-current faults.

For engineers reviewing the AP2181WG-7 datasheet, AP2181WG-7 pinout, AP2181WG-7 application, or AP2181WG-7 equivalent, key selection criteria include enable polarity (active-low), thermal shutdown threshold (+140°C), UVLO trip (1.9V typ), and package-specific thermal resistance (70°C/W for U-DFN2018-6).

Technical Context

The AP2181WG-7 integrates a low-R_DS(ON) N-channel MOSFET with precision current-sense FET architecture, enabling accurate 2.1A current limiting without external resistors. Its internal UVLO circuit disables the switch below 1.9V input, ensuring safe hot-insertion behavior in USB host systems.

It features a dedicated open-drain FLG output with 7ms blanking time to suppress false fault reporting during capacitive load turn-on transients. Thermal protection activates at +140°C with +25°C hysteresis, forcing cyclic shutdown until fault removal - no external thermal management required.

Key Specifications

Pinout & Package

AP2181WG-7 is packaged in U-DFN2018-6 - a 2.0mm × 1.8mm, 0.5mm pitch, thermally enhanced leadless package with exposed pad for GND connection and improved θ_JA (70°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-side USB power switch applications.

Compared with TUSB2036IRHBR and TPS2051BDBVR, AP2181WG-7 provides superior fault discrimination via integrated deglitch, lower R_DS(ON), and active-low enable compatibility with legacy USB controllers - making it optimal for discrete port protection in cost-sensitive consumer designs.

Availability

AP2181WG-7 is available at Aetrix Electronics and suitable for USB host port protection, laptop docking station power control, and set-top box peripheral interfaces requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for AP2181WG-7 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 high-volume consumer and industrial markets.

The AP2181/AP2191 product line was designed specifically for USB 2.0-compliant hot-swap power distribution, emphasizing low R_DS(ON), precise current limiting, and robust fault reporting in space-constrained portable applications.

FAQ

What is the maximum continuous output current rating for AP2181WG-7?

The AP2181WG-7 is rated for 1.5A maximum continuous load current under recommended operating conditions (T_A ≤ +85°C, V_IN = 5V). This rating accounts for thermal derating due to package limitations - the internal current limit remains fixed at 2.1A, but sustained operation above 1.5A risks thermal shutdown in standard PCB layouts.

Does AP2181WG-7 require external components for basic over-current protection?

No. AP2181WG-7 implements fully integrated over-current protection with no external components required. Its internal current-sense FET and 7ms deglitch circuit eliminate the need for sense resistors, RC filters, or pull-up resistors on FLG. Only a 0.1µF ceramic capacitor between IN and GND is mandatory for stability.

Can AP2181WG-7 be used in dual-role USB ports (e.g., USB-C DRP)?

No. The AP2181WG-7 is not recommended for dual-role ports where VBUS may be present on the OUT pin while the switch is disabled. Back-driving the output under such conditions can overstress the internal MOSFET. It is intended strictly for unidirectional, host-side power switching in USB 2.0 Type-A applications.

How does the FLG output behave during thermal shutdown versus over-current events?

The FLG output asserts low identically for both over-current and over-temperature faults, with identical 7ms deglitch timing. It remains low until both fault conditions clear. Unlike some competitors, AP2181WG-7 does not distinguish fault types on FLG - system firmware must infer root cause via timing correlation (e.g., rapid FLG toggling suggests thermal cycling; sustained low indicates persistent overload).