Diodes Incorporated PI3USB9281AGEEX

Overview

PI3USB9281AGEEX from Diodes Incorporated is a USB 2.0 port protection IC with integrated charger detection, USB On-The-Go (OTG) and Mobile HDMI Link (MHL) accessory identification, 1.7A over-current protection, 6.8V over-voltage protection, and I²C programmability. It operates from 3.0V to 5.5V supply and supports -40°C to +85°C ambient temperature, deployed in smartphone and tablet USB Type-A/B ports for intelligent power path control.

For engineers reviewing the PI3USB9281AGEEX datasheet, PI3USB9281AGEEX pinout, PI3USB9281AGEEX application, or PI3USB9281AGEEX equivalent, key selection criteria include BC1.2-compliant DCP/CDP/SDP detection accuracy, VBUSIN tolerance up to 28V, USB signal path R_ON ≤ 3.3Ω, OCP threshold at 1.7A, and dual-package support (UQFN-20L / CSP-15L) for space-constrained mobile designs.

Technical Context

The PI3USB9281AGEEX implements a dual-path analog switch architecture: one path routes D+/D− signals between host transceiver and connector (RON ≤ 3.3Ω, BW ≥ 1300MHz), while a second high-side FET controls VBUSOUT with programmable OVP (6.8V typ.) and OCP (1.7A typ.). Detection logic uses ID-pin resistance measurement (e.g., 1kΩ for MHL, 442kΩ for CEA-936 CarKit#1) combined with D+/D− voltage profiling per BC1.2 and Apple/Samsung fast-charge protocols.

Its I²C interface (slave address 0x45) enables real-time register access to Device Type (0x0A), Charger Status (0x0E), and Interrupt flags (0x03). The VBUSDET open-drain output asserts low when VBUSIN ≥ 3.5V, remaining active even during ENB=HIGH or VBAT=0V - enabling wake-up capability in dead-battery scenarios.

Key Specifications

Pinout & Package

PI3USB9281AGEEX is available in UQFN-20L (3 mm × 4 mm × 0.5 mm) and CSP-15L (1.5 mm × 2.0 mm) packages. This entry corresponds to the UQFN-20L variant (GEEX suffix).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar USB port protection and charger detection applications.

Compared with TPS65987D and IP5306, the PI3USB9281AGEEX uniquely balances legacy USB 2.0 compatibility, comprehensive charger taxonomy (including CarKit and MHL), robust 28V VBUSIN tolerance, and register-accessible diagnostics - making it optimal for micro-USB-equipped smartphones and tablets requiring deterministic, low-latency accessory awareness without USB-C complexity.

Availability

PI3USB9281AGEEX is available at Aetrix Electronics and suitable for smartphone charging port management, tablet USB host mode activation, portable media player sync control, and USB-C adapter companion functions requiring stable component supply across high-volume consumer electronics production.

Supply support for PI3USB9281AGEEX 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 company specializing in discrete, analog, and mixed-signal solutions for consumer, computing, communications, and industrial markets.

The PI3USB9281AGEEX belongs to Diodes' USB interface protection and detection product line, designed specifically to replace discrete resistor networks and GPIO-based detection schemes in space-constrained mobile devices with certified, production-ready USB accessory intelligence.

FAQ

What USB charging standards does PI3USB9281AGEEX support?

The PI3USB9281AGEEX natively supports Battery Charging Specification 1.2 (BC1.2) for DCP, CDP, and SDP detection; Apple 1A/2A/2.4A dedicated chargers; Samsung Fast Charge; YD/T-1951; and ANSI/CEA-936 CarKit#1 and #2. It identifies these via ID-pin resistance and D+/D− voltage profiling, with results reported in registers 0x0A and 0x0E.

How does PI3USB9281AGEEX handle over-voltage and over-current faults?

It integrates independent protection circuits: an OVP block triggers at 6.8V (typical) to disconnect VBUSOUT, and an OCP block trips at 1.7A (typical) to disable the charging FET. Both events set corresponding bits in the Interrupt register (0x03) and assert INTB, allowing firmware to log faults or initiate recovery without hardware latch-up.

Can PI3USB9281AGEEX operate with zero battery voltage?

Yes - the VBUSDET pin remains fully functional and the INTB interrupt responds to accessory attach/detach events even when VBAT = 0V. This enables cold-boot wake-up from USB insertion, critical for devices that must power on from dead-battery state using only VBUSIN energy.

What is the role of the ENB pin, and what happens when it is asserted high?

ENB is an active-low enable input. When pulled high, it disables all USB data switches (DPH/DNH, D+/D−), deactivates charger detection logic, and places VBUSOUT in high-impedance state - but VBUSDET remains powered and responsive. This allows hardware-level power gating while preserving VBUS presence monitoring capability.