Diodes Incorporated PI4IOE5V9538LEX

Overview

PI4IOE5V9538LEX from Diodes Incorporated is an 8-bit I²C/SMBus GPIO expander with active-low interrupt and reset, 5V-tolerant I/Os, 2.3V–5.5V supply operation, and 400 kHz I²C clock support. It serves as a parallel I/O extension for embedded control systems requiring push-button sensing, LED driving, fan control, or ACPI power switching in space-constrained industrial and consumer designs.

For engineers reviewing the PI4IOE5V9538LEX datasheet, PI4IOE5V9538LEX pinout, PI4IOE5V9538LEX application, or PI4IOE5V9538LEX equivalent, this device delivers configurable input/output direction per bit, polarity inversion, noise-filtered SCL/SDA inputs, power-on reset, and hardware address selection via A0/A1 - critical for multi-device I²C bus expansion without software arbitration overhead.

Technical Context

The PI4IOE5V9538LEX implements an I²C slave interface with fixed 7-bit address (0xE0–0xE6) determined by A0/A1 pins, supporting Standard (100 kHz) and Fast Mode (400 kHz) timing. Its register map includes Input Port (read-only), Output Port (write-only), Polarity Inversion, and Configuration registers - enabling per-pin I/O direction control and input data polarity flip without altering external circuitry.

It features an open-drain INT output activated on input state change (when configured as input), deasserted only upon reading the Input Port register or return to prior state. The RESET pin provides synchronous hardware initialization without cycling VCC, and internal POR ensures deterministic startup at VPOR = 1.16–1.41 V.

Key Specifications

Pinout & Package

TSSOP-16 (L) package: 4.4 mm × 5.0 mm, 0.65 mm pitch, lead-free and RoHS-compliant. Pin mapping validated per Diodes DS41536 Rev 1-2.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar I²C GPIO expander applications.

Compared with PCA9538APW and TCA6408APWR, the PI4IOE5V9538LEX offers unique polarity inversion per bit and integrated SCL/SDA noise filtering - reducing firmware complexity and external component count in industrial control and HMI applications where signal integrity and flexible input conditioning are critical.

Availability

PI4IOE5V9538LEX is available at Aetrix Electronics and suitable for ACPI power switching, multi-button keypad monitoring, LED status indication, and fan control applications requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for PI4IOE5V9538LEX 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 integrated circuits, specializing in high-performance, energy-efficient solutions for industrial, computing, and consumer markets.

The PI4IOE5V9538 belongs to Diodes' Pericom® interface and logic portfolio, designed specifically for reliable I²C-based peripheral expansion in space- and power-constrained embedded systems.

FAQ

What is the function of the A0 and A1 pins on the PI4IOE5V9538LEX?

A0 and A1 are hardware address select inputs that configure the two least-significant bits of the device's 7-bit I²C slave address (0xE0–0xE6). Setting A0/A1 to 00, 01, 10, or 11 allows up to four PI4IOE5V9538LEX devices to share the same I²C bus without address collision, eliminating software-based address arbitration.

Can the PI4IOE5V9538LEX drive LEDs directly, and what current limits apply?

Yes - IO pins can sink up to 10 mA per pin at VCC = 3.0 V (VOL = 0.5 V), with total device sink current limited to 200 mA. Each octal group (IO0–IO7) must not exceed 100 mA. For LED driving, connect cathodes to IOx and anodes to VCC via current-limiting resistors; avoid reverse-biasing I/Os when LEDs are off to minimize ICC.

How does the interrupt (INT) pin behave, and when is it asserted?

The open-drain INT pin asserts LOW when any IOx pin configured as an input changes state (rising or falling edge), provided the corresponding bit in the Configuration register is set to '1'. It remains asserted until the Input Port register is read by the host or the pin returns to its original logic level - enabling edge-triggered event detection without continuous polling.

Is the PI4IOE5V9538LEX suitable for automotive applications, and what qualifications does it hold?

The PI4IOE5V9538LEX is not AEC-Q100 qualified. Diodes states that automotive-grade versions require specific change control, PPAP capability, and IATF 16949 manufacturing - these are available under separate part numbers. This variant is intended for industrial, computing, and consumer applications operating within −40 °C to +85 °C.