NXP Semiconductors PCA9564PW,112

Overview

PCA9564PW,112 from NXP Semiconductors (formerly Philips Semiconductors) is a parallel-bus–to–I²C-bus controller IC that enables standard 8-bit parallel microcontrollers (e.g., 80C51-compatible) to interface with I²C-bus peripherals. It operates as both master and slave, supports standard/fast-mode I²C up to 400 kHz, features an internal 9 MHz oscillator, and accepts 2.3 V–3.6 V supply with 5 V–tolerant I/Os. It is used in embedded systems requiring protocol bridging without external timing components.

For engineers reviewing the PCA9564PW,112 datasheet, PCA9564PW,112 pinout, PCA9564PW,112 application, or PCA9564PW,112 equivalent, this device serves as a drop-in upgrade path from PCF8584 for low-voltage, higher-frequency I²C expansion-particularly where board space, BOM count, and voltage compatibility are critical constraints in industrial control and sensor hub designs.

Technical Context

The PCA9564PW,112 implements a full I²C state machine with hardware arbitration, START/STOP generation, clock stretching, and timeout detection-eliminating software overhead for bit-level I²C timing. Its register set (I2CSTA, I2CTO, I2CDAT, I2CADR, I2CCON) is accessed via 8-bit parallel bus using CE/WR/RD strobes and A0/A1 address select lines.

It supports four operational modes-Master Transmitter, Master Receiver, Slave Receiver, and Slave Transmitter-with status-driven interrupt service via INT pin. The internal oscillator eliminates external crystal requirements, and the time-out register (I2CTO) provides configurable SCL-low monitoring (range: ~114 µs to ~14.5 ms) to recover from bus lockups.

Key Specifications

Pinout & Package

PCA9564PW,112 is housed in a 20-pin TSSOP (SOT360-1) package with 0.65 mm pitch, exposed pad for thermal enhancement, and lead-free finish. Pin functions are identical across DIP/SO/TSSOP variants per datasheet Figure 1 and PIN DESCRIPTION table.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PCF8584T, PCA9564PW,112 delivers 4× faster I²C operation and eliminates external timing components; versus PCA9665BS,118, it offers pin-compatible TSSOP packaging and simpler register mapping at the cost of reduced bandwidth and no SMBus extensions-making it optimal for cost-sensitive, space-constrained 3.3 V retrofits.

Availability

PCA9564PW,112 is available at Aetrix Electronics and suitable for industrial automation, smart sensor hubs, legacy system upgrades, and multi-port I²C gateways requiring stable component supply and long-term manufacturability.

Supply support for PCA9564PW,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 leader focused on secure connectivity solutions for automotive, industrial, and IoT applications, with deep heritage in I²C and system-bus interface IP.

The PCA9564PW,112 belongs to NXP's legacy standard logic and interface portfolio, designed specifically to simplify I²C adoption in resource-constrained 8-bit microcontroller systems while maintaining backward compatibility with Philips' 80C51 ecosystem.

FAQ

What is the primary function of the PCA9564PW,112 in a system architecture?

The PCA9564PW,112 serves as a hardware protocol converter that bridges an 8-bit parallel microcontroller bus (e.g., 80C51-compatible) to the I²C-bus. It handles all I²C-specific timing, arbitration, START/STOP generation, and ACK/NACK signaling internally-allowing the host MCU to interact via simple parallel register reads/writes instead of bit-banged software I²C. This offloads timing-critical tasks and improves system determinism. The PCA9564PW,112 is especially valuable where MCU resources are limited or where strict I²C compliance must be guaranteed without firmware overhead.

Does the PCA9564PW,112 require an external crystal or oscillator?

No, the PCA9564PW,112 contains a fully integrated 9 MHz internal oscillator that generates all I²C timing signals. This eliminates the need for external crystals, capacitors, or clock sources-reducing BOM cost, PCB area, and layout complexity. After setting the ENSIO bit in the I2CCON register, the oscillator requires up to 500 µs to stabilize before I²C operations can begin. The PCA9564PW,112 does not support external clock input; its timing is solely derived from this internal source.

Can the PCA9564PW,112 operate with a 5 V microcontroller while powered from a 3.3 V supply?

Yes, the PCA9564PW,112 features 5 V–tolerant parallel I/O pins (D0–D7, CE, WR, RD, A0, A1, INT, RESET), allowing direct connection to 5 V logic levels even when VDD is supplied at 2.3–3.6 V. This enables seamless integration into mixed-voltage systems-for example, interfacing a legacy 5 V 8051 MCU with modern 3.3 V I²C peripherals-without external level shifters. However, the SCL and SDA pins remain standard open-drain I²C outputs and require appropriate pull-ups to the target I²C bus voltage (typically 3.3 V).

How does the PCA9564PW,112 handle I²C bus errors such as stuck SCL or SDA lines?

The PCA9564PW,112 implements hardware-based bus error recovery via its programmable time-out register (I2CTO). When enabled (TE bit = 1), the device monitors SCL-low duration and resets the I²C state machine if it exceeds (I2CTO[6:0] + 1) × 113.7 µs. Upon timeout, it loads status code 0x90 into I2CSTA, asserts INT, and releases SCL/SDA-allowing the host MCU to detect the fault via interrupt and initiate corrective action (e.g., external reset). This autonomous recovery prevents system hangs without requiring constant firmware polling, making the PCA9564PW,112 robust in electrically noisy or unattended deployments.

Is the PCA9564PW,112 pin-compatible with the older PCF8584?

No, the PCA9564PW,112 is not footprint-compatible with the PCF8584. Although functionally similar as parallel-to-I²C controllers, the PCA9564PW,112 uses a different pinout (e.g., DNU pin at position 9, relocated INT/RESET), operates at lower voltage (2.3–3.6 V vs. 4.5–5.5 V), and integrates an internal oscillator-eliminating the PCF8584's crystal pins. Migration from PCF8584 to PCA9564PW,112 requires PCB layout changes and firmware register mapping updates, but offers benefits including faster I²C speeds (360 kHz vs. 90 kHz), improved ESD/latch-up specs, and reduced external components. The PCA9564PW,112 is positioned as a functional upgrade-not a drop-in replacement.