NXP Semiconductors PCA9665PW,118

Overview

PCA9665PW,118 from NXP Semiconductors is a parallel-bus-to-I²C-bus controller IC enabling bidirectional communication between 8-bit parallel microcontrollers and the I²C-bus at up to 1 Mbit/s (Fast-mode Plus). It operates as master or slave, features a 68-byte buffer, 2.3–3.6 V supply, and 5 V-tolerant I/Os-used in industrial control modules requiring protocol bridging without external timing components.

For engineers reviewing the PCA9665PW,118 datasheet, PCA9665PW,118 pinout, PCA9665PW,118 application, or PCA9665PW,118 equivalent, this device delivers verified Fast-mode Plus I²C interface capability, software reset via parallel bus, internal oscillator with ±15 % accuracy, and TSSOP20 packaging compatible with space-constrained embedded designs.

Technical Context

The PCA9665PW,118 integrates an internal oscillator (28.5 MHz typical) that drives all I²C timing functions-eliminating external crystals or RC networks. Its register architecture separates four direct-access registers (I2CSTA, INDPTR, I2CDAT, I2CCON) and seven indirect-access registers (e.g., I2CSCLL, I2CADR, I2CPRESET), controlled via A0/A1 address pins and CE/WR/RD strobes.

It supports both Byte mode (single-byte transfers) and Buffered mode (up to 68 bytes), with interrupt- or polled-handshake operation. The SCL/SDA pins provide 25 mA sink current and are open-drain with 5 V tolerance, enabling interoperability with mixed-voltage I²C systems while maintaining SMBus compatibility.

Key Specifications

Pinout & Package

PCA9665PW,118 is housed in a plastic thin shrink small outline package (TSSOP20) with 20 leads, 4.4 mm body width, and standard JEDEC MO-153 footprint-compatible with automated SMT assembly and reflow profiles.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar parallel-to-I²C interface applications.

Compared with PCA9564PW,118, PCA9665PW,118 delivers 2.5× higher I²C throughput and eliminates firmware-level buffer management; versus PCA9665APW,118, it trades glitch-free restart for lower cost and identical functional coverage in most industrial control use cases.

Availability

PCA9665PW,118 is available at Aetrix Electronics and suitable for industrial PLCs, smart sensor hubs, legacy MCU upgrades, and automated test equipment requiring stable component supply across multi-year production cycles.

Supply support for PCA9665PW,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 leader focused on secure connectivity solutions for automotive, industrial, and IoT applications-with expertise in interface, power management, and secure MCU technologies.

The PCA9665PW,118 belongs to NXP's Fm+ parallel-bus-to-I²C controller product line, designed specifically to simplify I²C integration in resource-constrained microcontroller systems lacking native serial interfaces.

FAQ

What is the maximum I²C bus speed supported by the PCA9665PW,118?

The PCA9665PW,118 supports Fast-mode Plus (Fm+) operation at up to 1 Mbit/s. This is achieved using its internal 28.5 MHz oscillator and programmable SCL timing registers (I2CSCLL/I2CSCLH), enabling reliable communication with high-speed I²C peripherals such as fast EEPROMs or real-time clocks without external clock sources. The PCA9665PW,118 meets all Fm+ electrical specifications including 25 mA SCL/SDA sink capability.

Does the PCA9665PW,118 require an external crystal or RC network?

No, the PCA9665PW,118 does not require any external timing components. It contains an internal oscillator trimmed to ±15 % accuracy, which generates all necessary I²C timing signals-including START, STOP, ACK, and clock stretching. This eliminates BOM cost and PCB area associated with crystals, capacitors, or resistors, simplifying layout and improving reliability in vibration-prone industrial environments.

How does the 68-byte buffer in the PCA9665PW,118 improve system performance?

The 68-byte buffer in the PCA9665PW,118 enables Buffered mode operation, allowing the host microcontroller to issue multi-byte read/write commands in a single parallel bus transaction-reducing CPU intervention by up to 90 % compared to Byte mode. This significantly lowers interrupt load and improves determinism in time-critical applications like motor control feedback loops or sensor fusion pipelines.

Can the PCA9665PW,118 operate as both I²C master and slave simultaneously?

No-the PCA9665PW,118 operates as either master or slave at any given time, selected via software configuration of the I2CCON and I2CMODE registers. However, it supports multi-master arbitration and can dynamically switch roles across different transactions-for example, acting as master to configure sensors and then as slave to accept commands from a higher-level controller-without hardware changes.

Is the PCA9665PW,118 pin-compatible with the PCA9564?

Yes, the PCA9665PW,118 shares identical pinout and footprint with the PCA9564 (TSSOP20, SO20, HVQFN20 packages), enabling drop-in replacement in existing designs. However, key enhancements-including 1 Mbit/s speed, 68-byte buffer, General Call support, and software reset-require corresponding firmware updates to leverage the full capabilities of the PCA9665PW,118.