NXP Semiconductors PCA9554D,112

Overview

PCA9554D,112 from NXP Semiconductors is an 8-bit I²C-bus/SMBus GPIO expander in SO16 package, operating from 2.3 V to 5.5 V with 5 V-tolerant I/Os, 400 kHz clock support, and active-low open-drain interrupt output. It provides configurable input/output pins for ACPI power switches, push buttons, LEDs, and sensor interfaces in industrial control and embedded systems.

For engineers reviewing the PCA9554D,112 datasheet, PCA9554D,112 pinout, PCA9554D,112 application, or PCA9554D,112 equivalent, this page delivers verified register-level functionality, I²C address configuration (0x20–0x27), polarity inversion capability, and thermal performance data specific to the SO16 variant.

Technical Context

The PCA9554D,112 implements a synchronous I²C slave interface with four internal registers-Configuration, Input Port, Output Port, and Polarity Inversion-each accessible via command byte addressing. Its power-on reset initializes all I/Os as high-impedance inputs with weak pull-ups, and the interrupt output asserts when any configured input changes state relative to its Input Port register value.

Hardware address selection uses A0–A2 pins to set one of eight fixed I²C addresses (0x20–0x27); the PCA9554D variant uses base address 0x20. The device supports standard-mode (100 kHz) and fast-mode (400 kHz) I²C timing, includes noise filtering on SCL/SDA, and features ESD protection exceeding 2000 V HBM.

Key Specifications

Pinout & Package

PCA9554D,112 is supplied in SO16 (SOT162-1) package: plastic small outline, 16 leads, 7.5 mm body width, 1.27 mm lead pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PCA9554AD,112, the PCA9554D,112 offers lower base I²C address (0x20) for simpler bus initialization in small-scale designs; versus TCA9554APW,118, it provides NXP's AEC-Q100 qualification path and broader package availability including HVQFN.

Availability

PCA9554D,112 is available at Aetrix Electronics and suitable for industrial control panels, smart HVAC sensor nodes, ACPI power management subsystems, and LED status indicator banks requiring stable component supply across extended temperature ranges.

Supply support for PCA9554D,112 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

NXP Semiconductors is a global semiconductor company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and IoT applications.

The PCA9554 series belongs to NXP's I²C-bus I/O expander product line, designed specifically to simplify GPIO expansion in resource-constrained embedded systems while maintaining robustness in electrically noisy industrial environments.

FAQ

What is the default I²C address of the PCA9554D,112?

The PCA9554D,112 has a fixed base I²C slave address of 0x20. With A0, A1, and A2 pins grounded, the full 7-bit address becomes 0x20. Each combination of A0–A2 adds an offset (0–7), yielding addresses 0x20 through 0x27. This address scheme is documented in Figure 9 of the PCA9554_9554A datasheet and applies exclusively to the PCA9554D variant.

Does the PCA9554D,112 support 5 V logic levels on its I/O pins when powered from 3.3 V?

Yes, the PCA9554D,112 features 5 V-tolerant I/Os. When VDD = 3.3 V, IO0–IO7 can safely accept input voltages up to 5.5 V without damage or clamping, and maintain valid logic thresholds per VIH/VIL specifications. This allows direct interfacing with 5 V peripherals without external level-shifting circuitry - a key design advantage confirmed in Table 10 of the datasheet.

How does the interrupt output (INT) of the PCA9554D,112 behave during I/O reconfiguration?

The INT pin of the PCA9554D,112 may assert a false interrupt when an I/O is reconfigured from output to input if the external pin voltage differs from the stored value in the Input Port register. This occurs because the Input Port register reflects the last-read state, not real-time voltage. To avoid spurious interrupts, read the Input Port register immediately after changing the Configuration register for that pin - behavior explicitly described in Section 6.3 of the PCA9554_9554A datasheet.

Can the PCA9554D,112 drive LEDs directly, and what are the current limits?

Yes, the PCA9554D,112 can drive LEDs directly in sink mode (low-side) with up to 10 mA per I/O pin at VOL = 0.5 V (VDD = 3.0 V), per Table 10. However, total sourced current across all I/Os must not exceed 85 mA, and each pin must be externally limited to ≤25 mA. For reliable LED operation, use series resistors calculated for worst-case VDD (5.5 V) and forward voltage drop - design guidance is provided in Section 7 and Figure 15.

Is the PCA9554D,112 pin-compatible with the older PCF8574 series?

The PCA9554D,112 is pin-to-pin and I²C-bus address compatible with the PCF8574 series, but software changes are required due to architectural differences - including separate Configuration, Polarity Inversion, and Input Port registers. As stated in the General Description, "Although pin-to-pin and I²C-bus address compatible… software changes are required due to the enhancements and are discussed in Application Note AN469." No functional overlap or drop-in replacement claim is made.