Diodes Incorporated PI4IOE5V9554ALEX

Overview

PI4IOE5V9554ALEX from Diodes Incorporated is an 8-bit I²C/SMBus GPIO expander with interrupt and reset functionality, designed for system-level I/O expansion in space-constrained embedded applications. It operates from 2.3 V to 5.5 V, supports 400 kHz I²C Fast Mode, features 5 V-tolerant I/Os, active-low open-drain interrupt output, and polarity inversion register - enabling direct interface with mixed-voltage peripherals such as push buttons, LEDs, and sensors in industrial control panels.

For engineers reviewing the PI4IOE5V9554ALEX datasheet, PI4IOE5V9554ALEX pinout, PI4IOE5V9554ALEX application, or PI4IOE5V9554ALEX equivalent, key selection criteria include its 5 V-tolerant I/O capability, low standby current (≤700 µA at 5.5 V), hardware address pins (A0–A2) supporting up to eight devices on one bus, and integrated noise filtering on SCL/SDA lines for robust operation in electrically noisy environments.

Technical Context

The device implements a register-mapped I²C slave interface with four dedicated 8-bit registers: Input Port (read-only), Output Port (read/write), Polarity Inversion (read/write), and Configuration (read/write). All I/Os default to high-impedance inputs with 100 kΩ internal pull-ups at power-on reset, and individual direction control per bit is enabled via the Configuration register.

Interrupt generation is edge-triggered and asynchronous: the open-drain INT pin asserts when any configured input changes state, and deasserts only after the Input Port register is read - ensuring no event loss during polling. Addressing uses fixed 7-bit base (0x44 for PI4IOE5V9554, 0x7C for PI4IOE5V9554A) with A0–A2 providing three LSBs, allowing deterministic multi-device bus topology without software arbitration.

Key Specifications

Pinout & Package

PI4IOE5V9554ALEX is packaged in a 16-pin TSSOP (173 mil wide), with 0.65 mm pitch and exposed pad not connected internally. The package supports reflow soldering per JEDEC J-STD-020 and is RoHS-compliant, halogen-free, and lead-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PCA9554APW and TCA6408AIPWR, PI4IOE5V9554ALEX delivers unique value through native 5 V-tolerant I/Os, polarity inversion register, and lower standby current - reducing both external component count and firmware complexity in mixed-voltage industrial and automotive subsystems.

Availability

PI4IOE5V9554ALEX is available at Aetrix Electronics and suitable for industrial HMI panels, server baseboard management units, smart energy meters, and automotive body control modules requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for PI4IOE5V9554ALEX 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 manufacturing certified to IATF 16949 and product definitions aligned to AEC-Q100/101/200 standards.

The PI4IOE5V9554 series belongs to Diodes' Pericom-branded interface and logic portfolio, engineered specifically for reliable I²C-based I/O expansion in industrial automation, computing infrastructure, and automotive electronics where voltage flexibility and interrupt-driven responsiveness are critical.

FAQ

What is the I²C address of PI4IOE5V9554ALEX and how is it configured?

The PI4IOE5V9554ALEX has a fixed 7-bit I²C base address of 0x44. Pins A0, A1, and A2 serve as address LSBs, allowing eight unique addresses (0x44–0x4B) on the same bus. These pins must be externally pulled HIGH or LOW - no internal pull resistors exist, ensuring deterministic addressing without floating nodes.

Does PI4IOE5V9554ALEX support hot insertion or live bus connection?

No, PI4IOE5V9554ALEX does not support true hot insertion. Its I/Os are 5 V tolerant but lack bus-hold or power-on reset sequencing that guarantees safe initialization during dynamic bus attachment. Power must be stable before I²C communication begins, and SCL/SDA lines should not be driven while VCC is ramping.

How does the interrupt output behave when multiple inputs change simultaneously?

The INT pin asserts on the first detected input state change and remains active until the Input Port register is read - regardless of subsequent changes. This latched behavior ensures no event is missed during polling, but software must read the register to clear the interrupt and capture the full snapshot of all changed bits.

Can PI4IOE5V9554ALEX drive LEDs directly, and what are the current limits?

Yes, PI4IOE5V9554ALEX can drive LEDs directly in sink mode: each I/O supports up to 10 mA continuous sink current at VCC = 2.3 V (VOL ≤ 0.5 V), with total device sink limit of 100 mA. For 5 V LED strings, use external current-limiting resistors and verify voltage drop across the FET - do not exceed 25 mA per pin or 85 mA total sourced current.