Diodes Incorporated PI4IOE5V9554ZHEX

Overview

PI4IOE5V9554ZHEX from Diodes Incorporated is an 8-bit I²C-bus/SMBus GPIO expander with interrupt and reset functionality, operating from 2.3V to 5.5V supply, featuring 5V-tolerant I/Os, active-low open-drain INT output, and hardware address pins (A0–A2) enabling up to eight devices on one bus. It serves as a parallel I/O extension for microcontroller-based systems managing push buttons, LEDs, fans, and ACPI power switches in industrial control panels.

For engineers reviewing the PI4IOE5V9554ZHEX datasheet, PI4IOE5V9554ZHEX pinout, PI4IOE5V9554ZHEX application, or PI4IOE5V9554ZHEX equivalent, key selection criteria include I²C clock support up to 400 kHz, polarity inversion register, noise-filtered SCL/SDA inputs, power-on reset behavior, and TQFN-16 package thermal performance in space-constrained designs.

Technical Context

The device implements an I²C slave interface with fixed base address (0x40 for PI4IOE5V9554), supporting standard and fast-mode clocking (0–400 kHz). Its internal register map includes Input Port, Output Port, Polarity Inversion, and Configuration registers - all accessible via sequential read/write transactions without auto-increment.

Each of the eight bidirectional I/Os can be individually configured as input (with weak 100 kΩ pull-up) or output; input state changes trigger the open-drain INT signal, which clears upon reading the Input Port register. Power-on reset initializes all I/Os as inputs and sets default register values, while V_POR is specified at 1.16–1.41 V.

Key Specifications

Pinout & Package

PI4IOE5V9554ZHEX is housed in a 3 mm × 3 mm, 0.5 mm pitch TQFN-16 package with exposed thermal pad, optimized for compact PCB layouts and improved thermal dissipation in high-density embedded systems.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar GPIO expansion applications.

Compared with PCA9554APW and TCA6408APWR, PI4IOE5V9554ZHEX uniquely combines 5 V tolerance, polarity inversion, and SCL/SDA noise filtering in a thermally efficient TQFN-16 package - making it optimal for compact, mixed-voltage industrial interfaces requiring robust interrupt-driven I/O expansion.

Availability

PI4IOE5V9554ZHEX is available at Aetrix Electronics and suitable for industrial HMI panels, smart thermostats, server rack power management, and POS terminal peripheral interfaces requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for PI4IOE5V9554ZHEX 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 ICs, with design centers in Asia, Europe, and the U.S., serving industrial, computing, and consumer markets.

The PI4IOE5V9554 series belongs to Diodes' Pericom legacy portfolio of I²C interface and logic solutions, engineered specifically for reliable, low-power GPIO expansion in space- and noise-constrained embedded systems.

FAQ

What is the function of the A0–A2 pins on PI4IOE5V9554ZHEX?

A0, A1, and A2 are hardware address select inputs that determine the three LSBs of the device's 7-bit I²C slave address. With all combinations, up to eight PI4IOE5V9554 devices (or sixteen total when mixing with PI4IOE5V9554A) can share one I²C bus. These pins have no internal pull resistors and must be externally tied HIGH or LOW.

Does PI4IOE5V9554ZHEX support automatic increment addressing during I²C register access?

No. The PI4IOE5V9554ZHEX does not implement auto-increment addressing. After sending a command byte to select a register (e.g., 0x00 for Input Port), subsequent reads or writes remain directed to that same register until a new command byte is transmitted. This requires explicit re-sending of the command byte for multi-register operations.

How does the interrupt output behave after being triggered?

The open-drain INT pin goes LOW when any configured input pin changes state. It remains asserted until either the Input Port register is read (which clears the interrupt flag) or the input returns to its original logic level. Writing to the Input Port register has no effect - only reading clears the condition.

Can PI4IOE5V9554ZHEX drive LEDs directly without external current-limiting resistors?

No. While the device supports ±50 mA total output current and individual I/Os can sink up to ~10 mA at VOL = 0.7 V (VCC = 3.0 V), external current-limiting resistors are mandatory for LED driving to ensure consistent brightness and prevent overcurrent damage. The datasheet specifies maximum per-pin current limits and total device sink/source constraints.