Nexperia USA Inc. PCA9535PWJ

Overview

PCA9535PWJ from Nexperia is a low-voltage 16-bit I²C/SMBus GPIO expander with interrupt output, configuration registers, and 2.3 V to 5.5 V operation. It provides two 8-bit I/O ports (P0 and P1), open-drain INT output, hardware address pins (A0–A2), and power-on reset. Used in ACPI power switches, LED/fan control, and sensor interface subsystems where minimal interconnect and deterministic interrupt signaling are required.

For engineers reviewing the PCA9535PWJ datasheet, PCA9535PWJ pinout, PCA9535PWJ application, or PCA9535PWJ equivalent, key selection criteria include its 400 kHz Fast-mode I²C support, 25 mA push-pull output drive per I/O, 1 µA max standby current, and TSSOP24 package compatibility with space-constrained industrial and embedded designs.

Technical Context

The PCA9535PWJ implements a dual-port register architecture with four 8-bit register pairs: Input (00h/01h), Output (02h/03h), Polarity Inversion (04h/05h), and Configuration (06h/07h). All I/Os default to high-impedance inputs at power-up, and direction is set per-pin via the Configuration registers.

Its interrupt logic triggers on any edge change of configured input pins and resets upon reading the corresponding Input Port register or when port state reverts. The internal power-on reset circuit ensures deterministic initialization at VPORR ≈ 1.25–1.55 V, with td(rst) ≥ 300 ms required for reliable release.

Key Specifications

Pinout & Package

TSSOP24 (SOT355-1) package: plastic thin shrink small outline, 24 leads, 4.4 mm body width, surface-mount compatible with standard reflow profiles.

Key Features

Applications

Equivalent & Alternatives

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

Compared with the TCA6424A and PCA9555, the PCA9535PWJ offers the lowest standby current (1 µA), deterministic power-on reset behavior, and optimal balance of integration and cost for mid-scale I/O expansion in industrial and consumer applications.

Availability

PCA9535PWJ is available at Aetrix Electronics and suitable for industrial HMI panels, embedded sensor hubs, power management subsystems, and LED/fan control modules requiring stable component supply and long-term production continuity.

Supply support for PCA9535PWJ 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

Nexperia is a global semiconductor expert focused on high-volume, high-reliability logic, analog, and MOSFET solutions for automotive, industrial, and consumer markets.

The PCA9535 belongs to Nexperia's I²C GPIO expander product line, designed specifically for minimizing board space and interconnect complexity in resource-constrained embedded systems requiring deterministic interrupt-driven I/O expansion.

FAQ

What is the maximum number of PCA9535PWJ devices that can share one I²C bus?

Up to eight PCA9535PWJ devices can share a single I²C bus using the three hardware address pins (A0, A1, A2), each configurable as HIGH or LOW to generate unique 3-bit slave addresses. The base address is 0x20, and valid addresses range from 0x20 to 0x27. No software address remapping is required.

Does the PCA9535PWJ support hot insertion or live I²C bus connection?

No - the PCA9535PWJ does not support hot insertion. Its I²C interface lacks bus arbitration or glitch-free start/stop detection during voltage ramp-up. Connecting the device while the bus is active may cause undefined register states or communication lockup. Power sequencing must follow td(rst) ≥ 300 ms ramp-up requirement before initiating I²C transactions.

Can the INT pin be used as a general-purpose output?

No - the INT pin is strictly an open-drain interrupt output with no internal pull-up or bidirectional capability. It cannot be repurposed as a general-purpose I/O. Attempting to drive it high externally violates its open-drain specification and risks latch-up. For output functionality, use P0 or P1 port pins configured as outputs.

How is the polarity inversion register used in practice?

The polarity inversion register (04h/05h) flips the logical sense of input readings: writing '1' to bit N inverts the corresponding input bit in the Input Port register. This allows direct connection of active-low sensors (e.g., push buttons pulled high) without inverting software logic - reading '0' from the input register indicates button press, matching physical intent.