NXP Semiconductors PCA8575DB,112

Overview

PCA8575DB,112 from NXP Semiconductors is a 16-bit remote I/O expander IC for I²C-bus systems, providing quasi-bidirectional GPIO with latched outputs, active-low open-drain interrupt (INT), and 8 programmable slave addresses via AD0–AD2 pins. It operates from 2.3 V to 5.5 V, sinks up to 25 mA per I/O, and supports 400 kHz Fast-mode I²C communication. It is used in LED signage, industrial PLCs, and server management subsystems where microcontroller GPIO expansion is required.

For engineers reviewing the PCA8575DB,112 datasheet, PCA8575DB,112 pinout, PCA8575DB,112 application, or PCA8575DB,112 equivalent, key selection criteria include its 24-pin SSOP package, interrupt-driven port change detection, 16-bit quasi-bidirectional I/O architecture, 400 mA total sink capability, and compatibility with standard I²C timing and voltage levels across −40 °C to +85 °C.

Technical Context

The PCA8575DB,112 implements a dual-octet quasi-bidirectional I/O architecture: Port 0 (P00–P07) and Port 1 (P10–P17) each operate independently with internal current sources (IOH) and strong transient pull-ups (Itrt(pu)) enabling fast rising edges on heavily loaded outputs. Power-on reset initializes all I/Os as high-impedance inputs.

Its interrupt logic responds to any rising or falling edge on input pins and clears byte-wise - reading Port 0 data clears P0x-related interrupts only, while reading Port 1 clears P1x-related interrupts. This differs from the PCF8575, which clears INT only after both bytes are read.

Key Specifications

Pinout & Package

PCA8575DB,112 is housed in a 24-pin plastic shrink small outline package (SSOP24), body width 5.3 mm, lead pitch 0.65 mm (SOT340-1). Pin 1 is marked with index notch; device orientation follows JEDEC MO-150 standard.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar remote I/O expander applications.

Compared with PCF8575T/3,118 and TCA6424ARGJR, the PCA8575DB,112 delivers superior interrupt granularity for partial-port monitoring and enhanced rise-time performance for LED loads - making it optimal for signage, panel interfaces, and industrial I/O where deterministic, low-overhead event handling is critical.

Availability

PCA8575DB,112 is available at Aetrix Electronics and suitable for LED signage, industrial PLCs, and server management subsystems requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for PCA8575DB,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 PCA8575 product line was designed to extend microcontroller GPIO resources over standard I²C infrastructure while minimizing software overhead and board space - targeting cost-sensitive, high-reliability embedded systems.

FAQ

What is the maximum sink current per I/O pin on the PCA8575DB,112?

The PCA8575DB,112 supports up to 25 mA sink current per I/O pin at VDD = 4.5 V and VOL = 0.5 V. This rating enables direct LED driving without external drivers. The total package sink capability is 400 mA, limiting concurrent high-current operation across multiple pins - design must ensure aggregate current stays within this bound to avoid thermal derating or malfunction.

How does the PCA8575DB,112 interrupt (INT) behave during read operations?

The PCA8575DB,112 interrupt clears byte-wise: reading the first data byte (Port 0) clears interrupts associated with P00–P07 transitions only; reading the second byte (Port 1) clears interrupts for P10–P17 only. This differs from the PCF8575, which clears INT only after both bytes are read. The PCA8575DB,112 behavior allows selective acknowledgment of port-specific events without disturbing pending interrupts on the other port.

Can the PCA8575DB,112 operate with a 3.3 V microcontroller I²C bus?

Yes, the PCA8575DB,112 operates from 2.3 V to 5.5 V and features 5.5 V-tolerant I/Os. When powered at 3.3 V, its SDA and SCL pins are fully compatible with 3.3 V microcontrollers. Its I²C interface meets Fast-mode timing (400 kHz), and input thresholds (VIL ≤ 0.3×VDD, VIH ≥ 0.7×VDD) ensure reliable logic-level recognition across the full supply range.

What package type is used for the PCA8575DB,112?

The PCA8575DB,112 uses a 24-pin plastic shrink small outline package (SSOP24) with 0.65 mm lead pitch and 5.3 mm body width (SOT340-1). This package offers higher pin density than SO24 while maintaining surface-mount compatibility and thermal performance suitable for industrial ambient conditions.

Does the PCA8575DB,112 require external pull-up resistors on SDA and SCL lines?

Yes, the PCA8575DB,112 requires external pull-up resistors on both SDA and SCL lines, as specified by I²C bus standards. Its SDA and SCL pins are open-drain; pull-ups establish the HIGH state. Typical values range from 1.8 kΩ to 10 kΩ depending on bus capacitance and speed - 4.7 kΩ is commonly used for 400 kHz operation with ≤400 pF total bus capacitance.