NXP Semiconductors PCA6416AEVJ

Overview

PCA6416AEVJ from NXP Semiconductors is a 16-bit I²C-bus/SMBus I/O expander with dual-supply voltage translation (VDD(I2C-bus): 1.65–5.5 V; VDD(P): 1.65–5.5 V), open-drain interrupt output (INT), active-low reset (RESET), and 25 mA sink capability per port pin - used in battery-powered mobile systems for sensor interfacing, keypad scanning, and LED driving.

For engineers reviewing the PCA6416AEVJ datasheet, PCA6416AEVJ pinout, PCA6416AEVJ application, or PCA6416AEVJ equivalent, this device enables robust GPIO expansion across mismatched voltage domains (e.g., 1.8 V microcontroller ↔ 3.3 V peripherals), supports Fast-mode I²C (400 kHz), and delivers deterministic interrupt signaling without polling overhead.

Technical Context

The PCA6416AEVJ implements bidirectional level shifting via separate VDD(I2C-bus) and VDD(P) rails, allowing independent interface-side (SDA/SCL) and port-side (P0_0–P1_7) voltage operation - validated for combinations including 1.8 V/3.3 V, 2.5 V/5 V, and 3.3 V/1.8 V. Its register map includes four 8-bit register pairs: Configuration, Input, Output, and Polarity Inversion - all accessible via I²C address 0x20 or 0x21 (hardware-selectable via ADDR pin).

It features Schmitt-trigger inputs on SCL/SDA (hysteresis: 0.18 V @ 1.8 V, 0.33 V @ 3.3 V), internal power-on reset, and an open-drain INT output that asserts when any input state differs from its corresponding Input Port register value - latched until read or state reverts.

Key Specifications

Pinout & Package

VFBGA24 package (3 mm × 3 mm × 0.85 mm, ball pitch 0.5 mm); exposed center pad recommended as secondary ground or left floating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TCA6416A and PCA9535, the PCA6416AEVJ uniquely supports 5 V-tolerant I/Os and integrated bidirectional level translation - enabling direct connection to legacy 5 V sensors and actuators without additional components or layout revisions.

Availability

PCA6416AEVJ is available at Aetrix Electronics and suitable for industrial sensor hubs, battery-powered medical wearables, automotive body control modules, and LED status panels requiring stable component supply across extended temperature ranges (−40 °C to +85 °C).

Supply support for PCA6416AEVJ 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 leader specializing in secure connectivity solutions for automotive, industrial, and IoT applications - with over 30 years of expertise in I²C interface IP and mixed-signal integration.

The PCA6416A product line was designed specifically for low-power, multi-voltage embedded systems requiring reliable GPIO expansion without compromising signal integrity or increasing bill-of-materials complexity.

FAQ

What is the I²C slave address of PCA6416AEVJ and how is it configured?

The PCA6416AEVJ supports two fixed I²C slave addresses: 0x20 and 0x21. The ADDR pin (ball B5) selects the address - tied to GND for 0x20, or to VDD(P) for 0x21. This hardware configuration allows two PCA6416AEVJ devices to share the same I²C bus without address conflict, and is independent of software configuration. The R/W bit (LSB) is handled automatically by the I²C master during transaction initiation.

Does PCA6416AEVJ support true bidirectional level translation between I²C and port sides?

Yes, PCA6416AEVJ implements true bidirectional voltage-level translation: VDD(I2C-bus) sets the logic threshold for SDA/SCL (e.g., 1.8 V), while VDD(P) defines the port-side voltage (e.g., 3.3 V or 5 V). This allows seamless communication between a 1.8 V microcontroller and 5 V peripherals - confirmed in Table 4 of the datasheet for all combinations including 1.8 V/5 V and 3.3 V/1.8 V. No external translators are needed.

How does the INT pin behave when multiple input changes occur before the master reads the port registers?

The INT pin remains asserted (low) until the master reads the relevant Input Port register (00h or 01h) - regardless of how many input transitions occur during assertion. It does not latch individual events but indicates "at least one change occurred." Reading the register clears the interrupt condition, and subsequent changes will reassert INT. This behavior is deterministic and avoids missed interrupts in burst-change scenarios.

Can PCA6416AEVJ drive LEDs directly, and what are the current limitations?

Yes, PCA6416AEVJ can drive LEDs directly via its 16 port pins, each capable of sinking up to 25 mA when VDD(P) ≥ 2.5 V. However, total package current must remain within 100 mA (per datasheet Absolute Maximum Ratings), so simultaneous full-current drive across more than four pins requires derating. For optimal efficiency in battery-powered designs, configure LEDs as common-anode with current-limiting resistors tied to VDD(P).

What happens to the I/O pins during power-up or RESET assertion?

During power-up or RESET assertion, all 16 I/O pins (P0_0–P1_7) default to high-impedance inputs - verified by Configuration registers (06h/07h) powering up with all bits set to '1'. This no-glitch behavior prevents unintended activation of connected peripherals. The INT pin is released (high-impedance), and the I²C state machine resets to idle - ensuring predictable startup even under brown-out conditions.