NXP Semiconductors PCA9505DGG,118

Overview

PCA9505DGG,118 from NXP Semiconductors is a 40-bit I²C-bus I/O port expander with integrated 100 kΩ pull-up resistors on all I/Os, RESET and OE control inputs, and open-drain INT output. It operates from 2.3 V to 5.5 V, sources 10 mA/sinks 15 mA per output, and supports standard (100 kHz) and fast-mode (400 kHz) I²C communication. It is used in industrial control systems for LED driving, GPIO expansion, and interrupt-driven input monitoring.

For engineers reviewing the PCA9505DGG,118 datasheet, PCA9505DGG,118 pinout, PCA9505DGG,118 application, or PCA9505DGG,118 equivalent, key selection criteria include internal pull-up presence, TSSOP56 package compatibility, 40-bit banked I/O configurability, active-low reset/interrupt/enable signaling, and -40 °C to +85 °C industrial temperature rating.

Technical Context

The PCA9505DGG,118 implements five 8-bit I/O banks (IO0_0–IO4_7), each individually configurable as input or output via IOC registers. Its I²C interface uses auto-increment command addressing to sequentially access Input Port (IP), Output Port (OP), Polarity Inversion (PI), I/O Configuration (IOC), and Mask Interrupt (MSK) registers across all banks.

It features hardware-level interrupt generation triggered by unmasked input state changes, edge-sensitive OE control enabling PWM-based LED dimming (>80 Hz), and Power-On Reset plus active-low RESET pin initialization. All 40 I/Os default to high-impedance inputs at power-up, with internal 100 kΩ pull-ups distinguishing it from the PCA9506 variant.

Key Specifications

Pinout & Package

TSSOP56 package (SOT364-1), 6.1 mm body width, 0.5 mm pitch, 56-pin plastic thin shrink small outline package. Pin 1 index located at top-left corner; exposed pad not present (unlike HVQFN variant).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar I²C I/O port expansion applications.

Compared with PCA9505DGG,118, PCA9505DGGY offers identical functionality with enhanced moisture protection for SMT handling, while PCA9506DGG,518 removes internal pull-ups to reduce static current - making it preferable in power-constrained or externally biased systems.

Availability

PCA9505DGG,118 is available at Aetrix Electronics and suitable for industrial control, server management, and medical instrumentation requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for PCA9505DGG,118 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 specializing in secure connectivity solutions for automotive, industrial, and IoT applications, with leadership in I²C, SPI, and mixed-signal interface ICs.

The PCA9505 belongs to NXP's I/O port expander product line, designed specifically for robust, low-pin-count I²C-based GPIO expansion in space-constrained industrial and computing systems.

FAQ

What is the primary function of the PCA9505DGG,118 in an I²C system?

The PCA9505DGG,118 serves as a 40-bit I²C-bus I/O port expander that adds configurable digital inputs and outputs to microcontrollers with limited GPIO resources. It communicates via standard or fast-mode I²C, supports interrupt-driven input monitoring, and integrates 100 kΩ pull-up resistors on all I/Os - eliminating external components. Its role is to extend system I/O capability while maintaining bus efficiency and deterministic reset behavior.

Does the PCA9505DGG,118 require external pull-up resistors on its I²C bus lines?

Yes, the PCA9505DGG,118 requires external pull-up resistors on the SDA and SCL lines - the internal 100 kΩ pull-ups apply only to the 40 I/O pins (IO0_0 through IO4_7), not the I²C bus itself. Per I²C specification, SDA and SCL must be pulled up to VDD with values typically between 1.8 kΩ and 10 kΩ depending on bus capacitance and speed mode.

How does the interrupt (INT) pin of the PCA9505DGG,118 behave during input state changes?

The INT pin of the PCA9505DGG,118 is an open-drain active-low output that asserts when any unmasked input pin changes state. It remains asserted until the corresponding Input Port register (e.g., IP0 for IO0_x) is read - reading clears the interrupt condition. If multiple banks change simultaneously, all relevant IP registers must be read to deassert INT, ensuring precise event tracking without missed interrupts.

Can the PCA9505DGG,118 drive LEDs directly, and what are the current limits?

Yes, the PCA9505DGG,118 can drive LEDs directly: each totem-pole output sources up to 10 mA or sinks up to 15 mA at 5 V, with a total package current limit of 600 mA. This allows simultaneous driving of all 40 I/Os as LED anode/cathode controls. For optimal reliability, derate per-pin current under thermal constraints and verify voltage drop across series resistors for desired brightness.

What is the difference between PCA9505DGG,118 and PCA9506DGG,518?

The PCA9505DGG,118 includes 100 kΩ internal pull-up resistors on all 40 I/O pins; the PCA9506DGG,518 omits them to reduce leakage current and power consumption. Both share identical pinout, register map, timing, and TSSOP56 packaging. The PCA9505DGG,118 is preferred when external pull-ups are undesirable; the PCA9506DGG,518 suits low-power or push-pull-driven applications.