Diodes Incorporated PI4IOE5V9557LE

Overview

PI4IOE5V9557LE from Diodes Incorporated is an 8-bit I²C/SMBus GPIO expander with active-low reset, 5V-tolerant I/Os, 2.3V–5.5V supply operation, and TSSOP-16 packaging. It serves as a parallel I/O extension for embedded control systems requiring configurable inputs/outputs for push buttons, LEDs, fans, and ACPI power switches.

For engineers reviewing the PI4IOE5V9557LE datasheet, PI4IOE5V9557LE pinout, PI4IOE5V9557LE application, or PI4IOE5V9557LE equivalent, key selection criteria include I²C address configurability (A0–A2), polarity inversion register support, open-drain IO0 capability, 400 kHz Fast Mode I²C timing compliance, and low standby current (≤1 µA) in battery-sensitive designs.

Technical Context

The device implements a dual-register architecture: an 8-bit configuration register sets I/O direction per bit, while a separate 8-bit polarity inversion register flips input logic levels independently. All registers-including Input Port, Output Port, Polarity, and Configuration-are accessible via standard I²C Write Byte and Read Byte transfers.

It features hardware reset (active-low RESET pin with 25 ns minimum pulse width), power-on reset (VPOR = 1.16–1.41 V), noise filtering on SCL/SDA, and ESD protection (4 kV HBM, 1 kV CDM). The IO0 pin is open-drain with 1 µA high-level output current, while IO1–IO7 support 8–10 mA sink and 4 mA source capability at 2.3 V.

Key Specifications

Pinout & Package

Package: 16-pin TSSOP (173 mil wide), RoHS-compliant, lead-free, halogen-free, and green certified.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PCA9555DWR and TCA6424ARGJR, the PI4IOE5V9557LE uniquely combines 5V tolerance, open-drain IO0, polarity inversion, and sub-1 µA standby-making it optimal for compact, mixed-voltage, battery-aware embedded controllers where deterministic reset and flexible signal inversion are required.

Availability

PI4IOE5V9557LE is available at Aetrix Electronics and suitable for industrial control panels, smart home hubs, ACPI power management subsystems, and embedded fan controllers requiring stable component supply and long-term lifecycle assurance.

Supply support for PI4IOE5V9557LE 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 connectivity solutions for industrial, computing, and consumer markets.

The PI4IOE5V9557LE belongs to Diodes' Pericom® I²C GPIO portfolio, designed specifically for space-constrained, low-power embedded systems needing robust I/O expansion with hardware reset and mixed-voltage interoperability.

FAQ

What is the function of the IO0 pin, and how does it differ from IO1–IO7?

IO0 is an open-drain I/O pin with 1 µA high-level output current and 3 mA sink capability, optimized for LED anode control and wired-AND logic. In contrast, IO1–IO7 are push-pull capable with 4 mA source and 8–10 mA sink current, supporting direct drive of relays or logic inputs without external components.

How does the polarity inversion register improve system design flexibility?

The polarity inversion register (Register 2) allows individual input bits to be logically inverted without changing external circuitry-enabling direct interface with active-low sensors (e.g., door switches, limit switches) while preserving firmware logic consistency across multiple board revisions.

Can the PI4IOE5V9557LE operate reliably on a 3.3 V I²C bus while controlling 5 V peripherals?

Yes-the I/O pins are 5V-tolerant up to 6.0 V regardless of VCC level, and the SCL/SDA inputs accept VIH ≥1.8 V and VIL ≤0.81 V at 3.3 V operation. This allows seamless interfacing between a 3.3 V microcontroller and 5 V LEDs, relays, or sensors without level shifters.

What is the minimum RESET pulse width, and what happens if it is violated?

The minimum RESET pulse width is 25 ns. If shorter, the internal state machine may not fully initialize, causing undefined I/O states or I²C bus lockup. The device requires RESET to return HIGH before resuming normal operation; incomplete reset can result in stale register values or failed ACK responses.