Nexperia USA Inc. NCA9555PWJ

Overview

NCA9555PWJ from Nexperia is a low-voltage 16-bit I²C/SMBus GPIO expander with interrupt output, configurable I/O direction, polarity inversion, and internal pull-up resistors. It operates from 1.65 V to 5.5 V, supports 400 kHz Fast-mode I²C, and powers up with all 16 I/Os as high-impedance inputs-enabling immediate use in ACPI power switches, LED/fan control, and sensor interface subsystems.

For engineers reviewing the NCA9555PWJ datasheet, NCA9555PWJ pinout, NCA9555PWJ application, or NCA9555PWJ equivalent, key selection criteria include its open-drain INT output timing (tv(INT)), 25 mA per-pin push-pull drive capability, Schmitt-trigger SCL/SDA inputs (Vhys = 0.10 × VCC), latch-up immunity (>100 mA), and -40 °C to +85 °C industrial temperature range.

Technical Context

The NCA9555PWJ implements an I²C slave interface with eight hardware-configurable slave addresses via A0–A2 pins, supporting up to eight devices on one bus. Its register map includes four 8-bit register pairs (Input/Output/Polarity Inversion/Configuration) accessed via command-byte addressing, enabling atomic read/write of port data and real-time I/O reconfiguration without bus arbitration loss.

Each of the 16 I/Os (P0_0–P0_7, P1_0–P1_7) features independent direction control, polarity inversion, and input filtering with noise suppression on SCL/SDA. The open-drain INT output asserts active-low on any input state change, resets automatically upon reading the corresponding input register, and remains latched until cleared-ensuring reliable edge detection in interrupt-driven embedded systems.

Key Specifications

Pinout & Package

TSSOP24 (SOT355-1) package: 24-pin thin shrink small outline, 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 expansion applications.

Compared with PCA9555PW and TPS65987D, the NCA9555PWJ delivers superior industrial robustness (CDM >1000 V, latch-up >100 mA), guaranteed no-glitch power-up behavior, and a dedicated open-drain interrupt output-making it optimal for deterministic, low-overhead GPIO expansion in harsh environments.

Availability

NCA9555PWJ is available at Aetrix Electronics and suitable for industrial automation, HVAC control systems, and embedded security panels requiring stable component supply across extended product lifecycles.

Supply support for NCA9555PWJ 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 essential efficiency technologies-including logic, discretes, MOSFETs, and analog ICs-with manufacturing rooted in process expertise and sustainability.

The NCA9555 belongs to Nexperia's I²C GPIO expander product line, designed specifically to minimize interconnect complexity in resource-constrained embedded systems while maintaining industrial-grade reliability and wide voltage compatibility.

FAQ

What is the maximum number of NCA9555PWJ devices supported on a single I²C bus?

The NCA9555PWJ supports up to eight devices on one I²C bus using hardware address pins A0, A1, and A2. Each combination of HIGH/LOW on these three pins selects a unique 7-bit slave address from 0x20 to 0x27. No additional address translation or bus multiplexing is required-enabling scalable expansion without firmware changes.

Does the NCA9555PWJ require external pull-up resistors on SCL and SDA lines?

Yes-external pull-up resistors are mandatory on both SCL and SDA lines to ensure proper I²C bus operation. The device does not integrate internal pull-ups on these lines. Recommended values are 2.2 kΩ to 10 kΩ depending on bus capacitance and speed; values must comply with I²C Fast-mode specifications (≤400 pF total bus capacitance, ≤300 ns rise time).

How does the interrupt output (INT) behave when multiple GPIOs change state simultaneously?

The INT pin asserts active-low on the first detected input transition and remains asserted until the corresponding input port register is read-regardless of subsequent changes. Simultaneous transitions are captured in the input register but do not extend INT pulse width beyond tv(INT). Reading the port clears the interrupt condition, ensuring deterministic edge detection in multi-event scenarios.

Can the NCA9555PWJ drive LEDs directly without current-limiting resistors?

No-external current-limiting resistors are required for LED connections. Although the NCA9555PWJ supports 25 mA per pin, exceeding absolute maximum ratings risks latch-up or permanent damage. For example, a red LED with 1.8 V forward voltage at 3.3 V VCC requires ≥60 Ω (per Ohm's Law) to limit current to 25 mA. Always verify resistor value against LED Vf and desired brightness.