NXP Semiconductors PCAL6416AHF,128

Overview

PCAL6416AHF,128 from NXP Semiconductors is a 16-bit I²C-bus/SMBus I/O expander with dual-voltage rails (VDD(I2C-bus): 1.65–5.5 V; VDD(P): 1.65–5.5 V), programmable pull-up/pull-down resistors (100 kΩ), and maskable open-drain interrupt output. It provides bidirectional level translation between incompatible I/O voltage domains-e.g., 1.8 V microcontroller SDA/SCL and 3.3 V or 5 V peripherals-and supports latchable inputs for spurious-interrupt suppression in battery-powered sensor interfaces.

For engineers reviewing the PCAL6416AHF,128 datasheet, PCAL6416AHF,128 pinout, PCAL6416AHF,128 application, or PCAL6416AHF,128 equivalent, this device delivers Agile I/O features including per-pin drive strength control (four levels), input latching, interrupt status registers, and bank-selectable push-pull/open-drain outputs-critical for low-power embedded systems requiring flexible GPIO expansion without external logic or discrete biasing.

Technical Context

The PCAL6416AHF,128 implements a register-mapped I²C slave interface with 16 configurable GPIOs split across two 8-bit ports (P0_0–P0_7, P1_0–P1_7), each supporting independent direction control, polarity inversion, and interrupt masking. Its Agile I/O architecture includes dedicated registers for output drive strength (40h–43h), input latching (44h–45h), pull-up/pull-down enable and selection (46h–49h), and interrupt status (4Ch–4Dh).

It operates at up to 400 kHz Fast-mode I²C, features Schmitt-triggered SCL/SDA inputs (hysteresis: 0.18 V @ 1.8 V to 0.5 V @ 5 V), and integrates noise filtering on bus lines. Power-on reset initializes all I/Os as inputs, masks all interrupts by default, and ensures glitch-free startup-enabling reliable board bring-up in mixed-voltage industrial and portable designs.

Key Specifications

Pinout & Package

PCAL6416AHF,128 uses HWQFN24 (SOT994-1) package: 4 mm × 4 mm × 0.75 mm body, 24-terminal thermal-enhanced quad flat no-lead with exposed center pad (to be connected to ground or left floating). Pin numbering follows standard top-view index-area orientation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PCA6416APW,118 and TCA6416APWR, the PCAL6416AHF,128 uniquely combines interrupt masking at power-on, input latching, and per-pin drive strength-enabling robust, low-power, and layout-efficient GPIO expansion where deterministic interrupt handling and mixed-voltage interoperability are critical.

Availability

PCAL6416AHF,128 is available at Aetrix Electronics and suitable for industrial HMI, portable medical devices, automotive body electronics, and smart home hubs requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for PCAL6416AHF,128 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 focused on secure connectivity solutions for automotive, industrial, IoT, and mobile applications, with deep expertise in mixed-signal interface ICs and embedded processing.

The PCAL6416AHF,128 belongs to NXP's Agile I/O expander product line, designed specifically to simplify GPIO expansion in space-constrained, low-power, and mixed-voltage embedded systems-replacing discrete logic, level shifters, and bias resistors with a single configurable IC.

FAQ

What is the default I/O configuration at power-on for PCAL6416AHF,128?

At power-on, all 16 I/O pins (P0_0–P0_7 and P1_0–P1_7) of the PCAL6416AHF,128 are configured as high-impedance inputs, and all interrupt mask bits are set to 1-ensuring no spurious interrupts occur during system initialization. The Configuration registers (06h/07h) power up with 0xFF, and the Interrupt Mask registers (4Ah/4Bh) also default to 0xFF.

How does PCAL6416AHF,128 achieve bidirectional voltage level translation?

The PCAL6416AHF,128 achieves bidirectional level translation using separate supply rails: VDD(I2C-bus) sets the logic threshold for SCL/SDA inputs and defines the I²C-side voltage domain, while VDD(P) powers the 16 I/O ports. Internal circuitry references VDD(I2C-bus) to translate signals between the bus and port sides-enabling, for example, 1.8 V SCL/SDA communication with 5 V Port P outputs.

Can PCAL6416AHF,128 drive LEDs directly, and what is its maximum sink current?

Yes, the PCAL6416AHF,128 can drive LEDs directly: each of its 16 I/O pins supports up to 25 mA sink current in push-pull or open-drain mode. This eliminates external driver transistors for indicator LEDs in applications like HMI panels or status displays-provided total package current remains within thermal limits and VDD(P) is appropriately rated.

What is the purpose of the ADDR pin on PCAL6416AHF,128, and how is it used?

The ADDR pin on PCAL6416AHF,128 selects one of two I²C slave addresses (0x20 or 0x21) by connecting it to VDD(P) (HIGH) or GND (LOW). This allows two PCAL6416AHF,128 devices-or one PCAL6416AHF,128 and one PCA6416APW,118-to share the same I²C bus without address conflict, simplifying multi-expander system design.

Does PCAL6416AHF,128 include built-in ESD protection, and what levels are specified?

Yes, the PCAL6416AHF,128 includes on-chip ESD protection exceeding JEDEC standards: 2000 V Human-Body Model (HBM, JESD22-A114-A) and 1000 V Charged-Device Model (CDM, JESD22-C101). This enables robust handling during assembly and operation in environments with moderate electrostatic stress-reducing need for external TVS diodes on I/O lines.