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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Power Management - Specialized

Diodes Incorporated PI3USB9281AXWEX

Name: PI3USB9281AXWEX
Brand: Diodes Incorporated
SKU: PI3USB9281AXWEX
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: PI3USB9281AXWEX

Manufacturer:: Diodes Incorporated

Category:: Power Management - Specialized

Package:: 20-UFQFN Exposed Pad

Datasheet:: PI3USB9281AXWEX.pdf

Description:: IC USB 2.0 PORT DETECT 20UQFN

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Product details

Overview

PI3USB9281AXWEX from Diodes Incorporated is a USB 2.0 port protection IC with integrated charger detection, over-voltage (6.8 V OVP), over-current (1.7 A OCP), and USB switch functionality. It supports BC1.2 DCP/CDP/SDP, Apple 1A/2A/2.4A, Samsung Fast, CEA-936 CarKit #1/#2, and MHL/OTG accessory detection. Designed for mobile phone and tablet battery charging circuits, it tolerates up to 28 V on VBUSIN and operates from 3 V to 5.5 V supply.

For engineers reviewing the PI3USB9281AXWEX datasheet, PI3USB9281AXWEX pinout, PI3USB9281AXWEX application, or PI3USB9281AXWEX equivalent, key selection criteria include VBUSIN 28 V tolerance, I²C-programmable charger detection logic, dual-package availability (UQFN-20L / CSP-15L), and integrated power FET with 150 mΩ R_ON (CSP) or 200 mΩ R_ON (UQFN).

Technical Context

The PI3USB9281AXWEX implements a dual-path analog switch architecture: one path for USB 2.0 D+/D− signal routing (RON ≤ 3.3 Ω, BW = 1300 MHz), and a second high-side power switch for VBUSOUT control with programmable OVP (6.8 V) and OCP (1.7 A). Its detection engine uses ID-pin resistance measurement (e.g., 1 kΩ for MHL, 442 kΩ for CarKit Type 1) combined with D+/D− voltage profiling per BC1.2 and proprietary fast-charger protocols.

It features an always-on VBUSDET comparator (active even at VBAT = 0 V) and interrupt-driven I²C interface (slave address 0x4B) with register-mapped status reporting (Device Type 0x0A, Charger Status 0x0E). Detection timing is deterministic: CarKit detection completes in ≤130 ms, SDP/DCP/CDP in ≤200 ms, and ID-based accessory attach in ≤100 ms after ID pin stabilization.

Key Specifications

Parameter	Value and Actual Design Meaning
VBUSIN Tolerance	Up to 28 V - enables safe operation with USB 3.0 Power Delivery (20 V max) and transient surges without external clamping.
OVP Threshold	6.8 V typical - protects downstream battery and PMIC from over-voltage events on VBUSIN before enabling VBUSOUT.
OCP Threshold	1.7 A typical - limits current during short-circuit or overload on VBUSOUT, preventing thermal damage to PCB traces and charger IC.
USB Switch R_ON	2.5 Ω typical - ensures minimal insertion loss (<0.1 dB) and preserves USB 2.0 signal integrity up to 480 Mbps.
ID Pin Detection Range	0–3 MΩ - covers all BC1.2, Apple, Samsung, CEA-936, and MHL accessory ID resistances with ±5% accuracy.
I²C Interface	Fast-mode (400 kHz), slave address 0x4B - enables real-time configuration and status polling by baseband processor without CPU overhead.
Operating Temp	−40°C to +85°C - qualified for use in smartphones and tablets under sustained thermal load and ambient extremes.

Pinout & Package

PI3USB9281AXWEX is available in two RoHS-compliant packages: UQFN-20L (3 mm × 4 mm × 0.5 mm) and CSP-15L (1.5 mm × 2.0 mm, 0.4 mm pitch). The XWEX suffix denotes the UQFN-20L variant.

Pin/Terminal	Circuit Role	Design Meaning
D+ / D−	USB 2.0 Data Signal Path	Bi-directional analog switches routing D+/D− between connector and SoC transceiver; low R_ON, high bandwidth, and low crosstalk (−70 dB).
ID	Accessory Identification Input	High-impedance input measuring resistance to GND to classify OTG/MHL/CarKit/Apple/Samsung accessories per Table 4.
VBUSIN	Input Power Supply	28 V-tolerant input connected to USB connector VBUS; feeds internal OVP comparator and charger FET gate driver.
VBUSOUT	Output Power Switch	Switched output to charger IC source pin; enabled only after valid accessory detection and OVP/OCP pass.
VBAT	Battery Supply Input	3.0–5.5 V supply for internal logic and switch bias; remains functional down to 3.0 V for low-battery charging scenarios.
VDDIO	I/O Interface Supply	1.8–5.5 V rail powering INTB, SDA, SCL pins; decouples baseband I/O voltage from battery domain.
ENB	Enable Control (Active Low)	Hardware enable/disable; when HIGH, disables all detection and switching but retains VBUSDET wake-up capability.
INTB	Interrupt Output (Active Low)	CMOS output signaling accessory attach/detach, OVP/OCP event, or detection completion to baseband processor.
SCL / SDA	I²C Serial Interface	Standard Fast-mode I²C bus for reading Device Type (0x0A), Charger Status (0x0E), and configuring Control Register (0x02).
VBUSDET	VBUS Valid Indicator	Open-drain output pulled LOW when VBUSIN ≥ 3.5 V; used for system-level power sequencing independent of I²C.

Key Features

Feature	Design Value
Multi-standard charger detection	Simultaneous support for BC1.2 DCP/CDP/SDP, Apple 1A/2A/2.4A, Samsung Fast, CEA-936 CarKit #1/#2, and MHL - eliminates need for separate detection ICs.
Integrated high-side power FET	150 mΩ R_ON (CSP) / 200 mΩ R_ON (UQFN) switch with 2 A pulsed rating - replaces discrete MOSFET + gate driver + sense resistor.
Robust fault protection	6.8 V OVP + 1.7 A OCP + 3500 V HBM ESD (6500 V on VBUSIN/D+/D−/ID) - meets IEC 61000-4-2 Level 4 for consumer handhelds.
Low-power detection architecture	1 µA standby current (ISTANDBY) and 50–80 µA active static current - extends battery life during idle USB port monitoring.
I²C-configurable detection behavior	Control Register (0x02) allows manual vs. auto-switch mode, global interrupt mask, and reset via 0x1B - enables firmware-defined port policy.

Applications

Smartphone Charging System

Tablet USB Port Management

Use Scenario: Mobile phone detects and selects optimal charging current from wall adapter, PC, car charger, or MHL dock.

IC Role / Device Role / Timing Role: Acts as front-end USB port manager - performs ID-resistance and D+/D− voltage analysis within 200 ms, then asserts VBUSOUT and configures D+/D− path.

Use Value: Enables automatic 2.4 A Apple or 1.5 A Samsung Fast Charge without host CPU intervention, reducing boot-time charging latency.

Use Scenario: Tablet distinguishes between USB data sync (SDP), media charging (CDP), and high-power charging (DCP) while supporting OTG peripherals.

IC Role / Device Role / Timing Role: Provides dual-role port arbitration - detects OTG cable (ID = GND) and enables D+/D− path for host mode, or detects DCP and routes VBUSOUT to battery charger.

Use Value: Eliminates mechanical USB-C multiplexer and reduces BOM count by consolidating detection, switching, and protection into single UQFN-20L device.

Automotive Infotainment Dock

Portable Media Player Hub

Use Scenario: In-dash head unit identifies CEA-936 CarKit Type 1 (442 kΩ) or Type 2 (3 MΩ) and enables appropriate 5 V/12 V accessory power delivery.

IC Role / Device Role / Timing Role: Performs deterministic CarKit detection in ≤130 ms using ID-resistor measurement and VBUSIN validation - triggers dedicated power rail enable.

Use Value: Guarantees reliable accessory recognition across temperature (−40°C to +85°C) and voltage variation (VBUSIN 4–5.5 V), avoiding false disconnects.

Use Scenario: Portable media player connects to USB host for content transfer or to wall charger for battery top-up, while detecting MHL dongles for HDMI output.

IC Role / Device Role / Timing Role: Detects MHL accessory (ID = 200 kΩ) and activates D+/D− path for link training, while isolating VBUSOUT until MHL handshake completes.

Use Value: Prevents accidental battery discharge during MHL video streaming by gating VBUSOUT until protocol negotiation succeeds.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
TPS65987D	USB-C PD controller with integrated buck-boost; no native BC1.2/Apple detection; requires external ID resistor network.	Designed for USB-C PD sink/source negotiation, not micro-USB legacy port management.	Select when migrating to USB-C PD ecosystem; avoid for micro-USB designs requiring BC1.2 compliance.
MAX14637	BC1.2-only detector with no MHL/CarKit/Apple support; no integrated power switch; requires external OVP/OCP.	Targeted at cost-sensitive SDP/CDP/DCP detection only - lacks multi-protocol flexibility and protection integration.	Choose only if design requires minimal feature set and external protection is already present.

Compared with TPS65987D and MAX14637, PI3USB9281AXWEX uniquely combines micro-USB BC1.2/Apple/Samsung/CEA-936/MHL detection, integrated 1.7 A OCP + 6.8 V OVP, and I²C-configurable switching in a single UQFN-20L package - eliminating four discrete components in legacy smartphone designs.

Availability

PI3USB9281AXWEX is available at Aetrix Electronics and suitable for smartphone charging systems, tablet USB port management, automotive infotainment docks, and portable media player hubs requiring stable component supply across extended product lifecycles.

Supply support for PI3USB9281AXWEX 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 PI3USB9281AXWEX belongs to Diodes' USB port protection and charger detection product line, engineered specifically for space-constrained mobile devices needing robust, multi-protocol USB accessory identification and integrated power path control.

FAQ

What charger standards does PI3USB9281AXWEX support beyond BC1.2?

PI3USB9281AXWEX supports Apple 1A/2A/2.4A dedicated chargers (via 3 MΩ ID + D+/D− voltage signature), Samsung Fast chargers (recognized as BC1.2 DCP), CEA-936 CarKit Type 1 (442 kΩ) and Type 2 (3 MΩ), and Mobile High-Definition Link (MHL) accessories (200 kΩ ID). It does not support USB-C PD or QC protocols.

How does the VBUSDET pin function when the device is disabled (ENB = HIGH)?

VBUSDET remains fully operational even when ENB = HIGH (device disabled): it outputs LOW when VBUSIN ≥ 3.5 V and high-impedance when VBUSIN < 3.4 V. This allows system-level power sequencing and wake-up triggering independent of the IC's detection state, with guaranteed 30 µs response time.

Can PI3USB9281AXWEX be used with USB 3.0 SuperSpeed signals?

No. PI3USB9281AXWEX is designed exclusively for USB 2.0 (480 Mbps) D+/D− signal paths. Its analog switch bandwidth (1300 MHz) and capacitance (4.0 pF) meet USB 2.0 requirements but do not support USB 3.0 SuperSpeed TX/RX differential pairs, which require separate high-speed routing and impedance control.

What is the minimum VBUSIN voltage required to initiate charger detection?

Charger detection initiates only after VBUSIN reaches ≥3.5 V, as confirmed by the VBUSDET pin going LOW. Below this threshold, the detection engine remains inactive regardless of ID pin state or D+/D− voltage. This prevents false detections from noise or floating VBUS lines.

PI3USB9281AXWEX Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: -

Package/Case:: 20-UFQFN Exposed Pad

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Applications:: Mobile Communications

Current - Supply:: -

Voltage - Supply:: 3V ~ 5.5V

Operating Temperature:: -40°C ~ 85°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 20-UQFN (3x4)

PI3USB9281AXWEX FAQ

1.How can I place an order for PI3USB9281AXWEX through Aetrix?

Please submit a Request for Quotation (RFQ) for PI3USB9281AXWEX on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for PI3USB9281AXWEX reliable?

The price and inventory of PI3USB9281AXWEX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for PI3USB9281AXWEX is usually 5 days.

3.What payment methods are accepted for PI3USB9281AXWEX?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for PI3USB9281AXWEX transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for PI3USB9281AXWEX?

PI3USB9281AXWEX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your PI3USB9281AXWEX order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for PI3USB9281AXWEX?

For technical support, including PI3USB9281AXWEX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your PI3USB9281AXWEX requirements.

6.How does Aetrix verify that PI3USB9281AXWEX is sourced from the original manufacturer or authorized distributors?

All PI3USB9281AXWEX products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that PI3USB9281AXWEX meets industry standards.

7.What is the process for return or replacement of PI3USB9281AXWEX?

All PI3USB9281AXWEX units undergo pre-shipment inspection (PSI). If there is an issue with PI3USB9281AXWEX, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The PI3USB9281AXWEX part is unused and in its original packaging.

Return procedure for PI3USB9281AXWEX:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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