Diodes Incorporated PI4IOE5V9539ZDEX

Overview

PI4IOE5V9539ZDEX from Diodes Incorporated is a 16-bit I²C/SMBus GPIO expander with interrupt and active-low reset, operating from 2.3V to 5.5V, featuring 5V-tolerant I/Os, open-drain interrupt output, and dual 8-bit configuration/polarity registers. It serves as a system-side I/O extension for ACPI power switches, push buttons, LEDs, and sensor interfaces in space-constrained embedded control applications.

For engineers reviewing the PI4IOE5V9539ZDEX datasheet, PI4IOE5V9539ZDEX pinout, PI4IOE5V9539ZDEX application, or PI4IOE5V9539ZDEX equivalent, key selection criteria include I²C address configurability (A0/A1), 400 kHz Fast Mode support, low standby current (0.25 µA), 5V I/O tolerance, and TQFN-24 package thermal performance.

Technical Context

The PI4IOE5V9539ZDEX implements a dual-octet architecture with independent 8-bit input/output, polarity inversion, and direction configuration registers-each pair (Port 0/Port 1) accessible via sequential I²C reads/writes. Its interrupt logic triggers only on state changes of input-configured pins and clears upon reading the corresponding input port register.

It supports full I²C Standard Mode (100 kHz) and Fast Mode (400 kHz), includes noise filtering on SCL/SDA inputs, and features power-on reset (VPOR = 1.16–1.41 V) plus an asynchronous active-low RESET pin that reinitializes register states and the I²C state machine without cycling VCC.

Key Specifications

Pinout & Package

PI4IOE5V9539ZDEX is housed in a 24-contact, 4 mm × 4 mm Very Thin Quad Flat No-Lead (TQFN) package with exposed thermal pad (ZD suffix), optimized for compact PCB layouts and improved thermal dissipation in high-density designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PCA9539D and TCA6424AIPWR, PI4IOE5V9539ZDEX delivers unique value in 5V-tolerant I/O operation, sub-µA standby current, and integrated polarity inversion-making it optimal for cost-sensitive, battery-aware, and mixed-voltage industrial I/O expansion where minimal external components are critical.

Availability

PI4IOE5V9539ZDEX is available at Aetrix Electronics and suitable for industrial HMI panels, server management controllers, and battery-powered sensor gateways requiring stable component supply, RoHS-compliant packaging, and long-term lifecycle assurance.

Supply support for PI4IOE5V9539ZDEX 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 power management, signal integrity, and connectivity applications.

The PI4IOE5V9539 belongs to Diodes' I/O expansion product line, engineered specifically for low-power, space-constrained embedded systems needing reliable I²C-based peripheral interfacing with minimal external components.

FAQ

What is the minimum pulse width required on the RESET pin to trigger a hardware reset?

The RESET pin requires a LOW pulse width of at least 25 ns to initiate a full device reset. During this time, the internal state machine and all registers-including I/O direction, output values, and polarity settings-are restored to their power-on defaults. The device remains in reset until RESET returns HIGH, after which I²C communication resumes immediately without requiring VCC cycling.

Can the PI4IOE5V9539ZDEX drive LEDs directly, and what is the maximum sink current per I/O?

Yes, each I/O can sink up to 9 mA at VOL = 0.5 V (VCC = 2.3 V) or 11 mA at VOL = 0.7 V (VCC = 2.3 V), with absolute maximum per-pin current limited to 25 mA. For LED driving, configure the I/O as output and connect the LED anode to VCC through a current-limiting resistor; the I/O sinks current when driven LOW. Total device sink current must not exceed 200 mA across all 16 pins.

How does the interrupt mechanism work, and how is it cleared?

The open-drain INT pin asserts LOW when any input-configured I/O changes state. The interrupt remains active until the corresponding input port register (Port 0 or Port 1) is read via I²C-reading one port does not clear interrupts from the other port. This allows independent handling of two 8-bit input groups. No external interrupt controller is needed; the MCU responds directly to the INT signal edge and clears it by performing the appropriate register read.

Is the PI4IOE5V9539ZDEX compatible with standard I²C Fast Mode (400 kHz) timing requirements?

Yes, the PI4IOE5V9539ZDEX fully complies with I²C Fast Mode specifications: tLOW and tHIGH minima of 1.3 µs and 0.6 µs respectively, SCL/SDA rise/fall times ≤300 ns, and noise filter rejection of spikes ≤50 ns. It supports guaranteed communication up to 400 kHz across the full −40 °C to +85 °C temperature range with VCC = 2.3–5.5 V, meeting JEDEC and NXP I²C timing standards without external timing compensation.