Diodes Incorporated AP2171FMG-7

Overview

AP2171FMG-7 from Diodes Incorporated is a single-channel, active-high enable, current-limited high-side power switch optimized for USB 2.0 and hot-swap applications. It delivers 1.5A accurate current limiting, 95mΩ typical R_DS(ON) at 5V input, and integrated short-circuit/thermal protection with 7ms deglitch on the open-drain FLG output. Used in USB downstream ports of laptops and docking stations to manage inrush and fault reporting without external components.

For engineers reviewing the AP2171FMG-7 datasheet, AP2171FMG-7 pinout, AP2171FMG-7 application, or AP2171FMG-7 equivalent, this device supports precise overcurrent response (1.5A typ), controlled 0.6ms rise time, reverse current blocking, UVLO (1.9V typ), and low 1µA shutdown current - critical for reliable USB port power management and hot-plug robustness.

Technical Context

The AP2171FMG-7 integrates a low-R_DS(ON) N-channel MOSFET with internal current-sense FET architecture, eliminating external sense resistors while maintaining accurate 1.5A current limiting across -40°C to +85°C. Its thermal shutdown triggers at ~145°C with 25°C hysteresis, enabling safe cycling under sustained overload.

It features an active-high EN input, open-drain FLG output with 7ms blanking to suppress false trips during capacitive load turn-on, and undervoltage lockout that disables the switch below 1.9V. All IN and OUT pins are internally paralleled, requiring external tie-together for SO-8, MSOP-8EP, and SOT25; U-DFN2018-6 uses dedicated IN/OUT terminals.

Key Specifications

Pinout & Package

AP2171FMG-7 is packaged in a 6-pin U-DFN2018-6 (2.0mm × 1.8mm, 0.5mm pitch) with exposed thermal pad. The package supports high thermal efficiency (θ_JA = 70°C/W) when the exposed pad is soldered to PCB ground plane via ≥3 thermal vias.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TCK107AG,314 and TPS2051BDBVR, AP2171FMG-7 uniquely combines reverse current blocking, 1µA shutdown current, and 7ms FLG deglitch in a 2.0×1.8mm U-DFN package - making it optimal for space-constrained, battery-aware USB host designs requiring autonomous fault handling.

Availability

AP2171FMG-7 is available at Aetrix Electronics and suitable for USB 2.0 port protection, laptop docking station power distribution, and industrial hot-swap module control requiring stable component supply, long-term lifecycle support, and RoHS-compliant green packaging.

Supply support for AP2171FMG-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 high-reliability power management, signal integrity, and protection solutions for consumer, computing, and industrial markets.

The AP2171 belongs to Diodes' USB Power Switch product line, engineered specifically for robust, low-footprint, single-channel hot-swap control in USB 2.0-compliant systems - emphasizing precision current limiting, thermal resilience, and minimal external component count.

FAQ

What is the function of the FLG pin on AP2171FMG-7?

The FLG pin is an open-drain fault indicator that asserts low during overcurrent or thermal shutdown events after a 7ms deglitch timeout. It remains low until both fault conditions are cleared, and requires an external pull-up resistor (typically 10kΩ) to V_IN or system logic rail. This pin enables real-time system-level fault detection without polling or additional sensing circuitry.

Can AP2171FMG-7 be used in dual-role USB ports (e.g., charging + data)?

No - AP2171FMG-7 is not recommended for dual-purpose ports such as shared HDMI/MHL or USB-C alternate mode interfaces where voltage may be present on OUT while the switch is disabled. Back-driving the output under disabled state risks overstress due to lack of bidirectional blocking, as confirmed in Diodes' Application Information section on non-recommended use cases.

How does the 7ms FLG deglitch improve system reliability?

The 7ms deglitch prevents false FLG assertions caused by transient inrush currents during connection of large capacitive loads (e.g., 100µF+ USB peripherals). By ignoring short-duration overcurrent spikes, it eliminates spurious interrupts or port resets - ensuring only sustained faults trigger system-level responses, which improves plug-and-play robustness in consumer electronics.

What thermal design considerations apply to the U-DFN2018-6 package?

The U-DFN2018-6 exposes a thermal pad that must be soldered to a minimum 1.0" × 1.4" copper ground plane on the PCB bottom layer using ≥3 thermal vias (0.3mm diameter, filled or plated). Per Diodes' datasheet Note 8, this achieves θ_JA = 70°C/W; omitting the pad or insufficient vias raises junction temperature beyond safe limits under 1A continuous load at +85°C ambient.