NXP Semiconductors PCAL6524EV-ARD

Overview

PCAL6524EV-ARD from NXP Semiconductors is an Arduino-compatible daughterboard evaluation kit built around the PCAL6524 24-bit I²C-bus I/O expander IC. It provides direct access to all 24 configurable I/O pins across three 8-bit ports (P0–P2), supports Fast-mode Plus I²C (1 MHz), includes on-board four-digit LED display driven via MAX V CPLD, and features four user LEDs, four tactile switches, and dual I/O expansion headers (J6/J7) for prototyping.

For engineers reviewing the PCAL6524EV-ARD datasheet, PCAL6524EV-ARD pinout, PCAL6524EV-ARD application, or PCAL6524EV-ARD equivalent, this board enables rapid validation of PCAL6524 register configuration, interrupt behavior, GPIO direction/polarity/latch control, and real-time I/O state monitoring - especially in embedded host environments with Arduino R3-compliant interfaces such as i.MX RT1050, LPC55S69, and i.MX 8M Mini EVKs.

Technical Context

The PCAL6524EV-ARD implements a hardware abstraction layer between host development boards and the PCAL6524 I/O expander, using dedicated Arduino port signals for I²C (SDA/SCL), RESET, ADDR, and INT. Its MAX V CPLD (5M80ZE64C5N) decodes and drives the on-board 4-digit LED display from P0/P1, while P2 connects directly to discrete LEDs and switches - all accessible externally via J6 (16-bit) and J7 (8-bit) headers.

Power is sourced entirely from the host's 5 V Arduino rail, regulated locally to 3.3 V (U3) and 1.8 V (U4) for the PCAL6524 and CPLD. The board supports three operational modes for the LED display - Direct Write (GUI-controlled digit values), Count (up/down counter at 7.6 Hz or 61 Hz), and Idle (displaying "−") - all managed via six CPLD control lines routed from Arduino digital pins D2–D8.

Key Specifications

Availability

PCAL6524EV-ARD is available at Aetrix Electronics and suitable for embedded prototyping, I/O expansion validation, and educational labs requiring stable component supply, quick-turn evaluation of NXP's PCAL6524 I/O expander, and interoperability testing with Arduino R3-compatible host platforms.

Supply support for PCAL6524EV-ARD 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 PCAL6524EV-ARD belongs to NXP's PCAL6xxx family evaluation platform series, designed specifically to accelerate development with their ultra-low-voltage, translating I²C I/O expanders - emphasizing ease of register-level testing, interrupt debugging, and real-world GPIO interface validation.

FAQ

What is the primary function of the PCAL6524EV-ARD?

The PCAL6524EV-ARD is an Arduino R3-compatible daughterboard that hosts the PCAL6524 24-bit I²C I/O expander for rapid evaluation. It enables engineers to test register configuration, interrupt generation, GPIO direction/polarity/latch settings, and real-time I/O state changes - all through a Windows GUI application when paired with supported NXP EVKs like the i.MX RT1050 or LPC55S69.

Which host development boards are officially supported with the PCAL6524EV-ARD?

The PCAL6524EV-ARD is fully compliant with three NXP evaluation kits: the i.MX RT1050 EVK, LPCXpresso55S69 Development Board, and i.MX 8M Mini LPDDR4 EVK (via IMX8MMINI-IARD interposer). Each platform runs the same GUI software and firmware stack, allowing consistent PCAL6524EV-ARD operation across heterogeneous host MCUs without hardware modification.

Does the PCAL6524EV-ARD require external power or programming?

No - the PCAL6524EV-ARD draws all operating power (5 V) from the host board's Arduino port and requires no standalone power supply. It contains no programmable flash; its MAX V CPLD is pre-configured and controlled dynamically by the GUI via Arduino digital pins. Firmware resides on the host EVK, not on the PCAL6524EV-ARD itself.

How are the 24 I/O pins of the PCAL6524 accessed on the PCAL6524EV-ARD?

All 24 I/O pins are physically accessible: P0 and P1 (16 pins) route through the MAX V CPLD to drive the on-board 4-digit LED display and are also exposed on J6; P2 (8 pins) connects directly to four LEDs, four switches, and is fully available on J7. Both J6 and J7 headers provide unbuffered, 1:1 electrical access to the PCAL6524EV-ARD's underlying PCAL6524 pins.

Can the PCAL6524EV-ARD be used without the GUI software?

Yes - the PCAL6524EV-ARD functions as a standard I²C peripheral. Engineers may communicate directly with the PCAL6524 IC using custom firmware on any Arduino-compatible or I²C-capable host, reading/writing registers over SDA/SCL. The GUI is optional; jumpers JP1 (INT monitor) and JP2 (LED enable) allow hardware-level configuration independent of software.