NXP Semiconductors PCA9564D,112

Overview

PCA9564D,112 from NXP Semiconductors (formerly Philips Semiconductors) is a parallel-bus-to-I²C-bus protocol converter IC that enables 8-bit parallel microcontrollers without native I²C support to interface with I²C 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 2.3–3.6 V supply with 5 V tolerant I/Os - used in industrial control modules requiring legacy parallel CPU expansion.

For engineers reviewing the PCA9564D,112 datasheet, PCA9564D,112 pinout, PCA9564D,112 application, or PCA9564D,112 equivalent, key selection considerations include its dual master/slave operation, internal clock source eliminating external crystal, 5 V tolerant D0–D7 bus pins, interrupt-driven or polled I²C transaction handling, and compatibility with Intel 80C51-style parallel timing.

Technical Context

The PCA9564D,112 implements a full hardware I²C state machine with arbitration, START/STOP generation, ACK/NACK handling, and timeout detection - all managed autonomously without firmware intervention. Its register set (I2CSTA, I2CTO, I2CDAT, I2CADR, I2CCON) is accessed via A0/A1 address decoding on the parallel bus and supports byte-wise I²C data transfer using RD/WR/CE handshaking.

It integrates an internal 9 MHz oscillator for precise I²C timing, enabling programmable master clock rates from 36 kHz to 881 kHz (per CR2:CR0 bits), while slave mode synchronizes automatically to any I²C clock up to 400 kHz. The device uses open-drain SDA/SCL outputs with internal pull-up capability and provides active-low open-drain INT output for interrupt-driven host coordination.

Key Specifications

Pinout & Package

PCA9564D,112 is supplied in a 20-pin plastic SO (Small Outline) package per drawing SOT163-1, with 1.27 mm pitch, body size 12.8 mm × 7.5 mm, and gull-wing leads suitable for reflow soldering.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PCF8584T, PCA9564D,112 delivers 4× faster I²C master operation and eliminates external timing components; versus PCA9665BS, it offers smaller SO20 packaging and simpler register mapping at the cost of lower maximum speed and no SMBus extensions.

Availability

PCA9564D,112 is available at Aetrix Electronics and suitable for industrial PLCs, legacy MCU upgrades, automated test equipment, and multi-bus gateways requiring stable component supply across extended product lifecycles.

Supply support for PCA9564D,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.

The PCA9564D,112 belongs to NXP's legacy I²C interface controller family, designed specifically to extend parallel-bus microcontroller capabilities into I²C-based sensor and peripheral ecosystems with minimal hardware overhead.

FAQ

What is the function of the DNU pin on the PCA9564D,112?

The DNU (Do Not Use) pin on the PCA9564D,112 is internally pulled low and must be left unconnected (floating) per the datasheet. It serves no functional purpose in normal operation and connecting it externally may cause undefined behavior or violate internal biasing conditions. This pin appears on pin 9 of the SO20 package and corresponds to pin 6 in the HVQFN variant.

Does the PCA9564D,112 support both master and slave I²C operation simultaneously?

No, the PCA9564D,112 does not operate as master and slave simultaneously. It supports either master or slave mode at any given time, selected via software configuration of the ENSIO and AA bits in the I2CCON register. While it can switch dynamically between roles (e.g., master to initiate communication, then slave to accept configuration), concurrent dual-role operation is not implemented in the hardware state machine.

How does the internal oscillator of the PCA9564D,112 affect I²C timing accuracy?

The PCA9564D,112 uses a factory-trimmed internal 9 MHz oscillator to generate all I²C timing signals, resulting in ±1.5% typical frequency tolerance across voltage and temperature. This eliminates external crystal drift and load capacitance variability, ensuring consistent SCL HIGH/LOW times - critical for reliable fast-mode (400 kHz) operation without manual calibration.

Can the PCA9564D,112 interface directly with a 5 V microcontroller parallel bus?

Yes, the PCA9564D,112 features 5 V tolerant D0–D7, RD, WR, CE, A0, and A1 pins, allowing direct connection to 5 V parallel buses without level-shifting circuitry. Its VDD supply remains at 2.3–3.6 V, so only the I/O pins - not the power domain - tolerate 5 V, preserving logic compatibility while simplifying interconnect design.

What happens if the PCA9564D,112 encounters an I²C bus timeout condition?

When the PCA9564D,112 detects SCL held low beyond the programmed timeout period (set via I2CTO register), it resets the I²C state machine, loads status code 90H into I2CSTA, asserts the INT pin, and releases SCL/SDA lines. The host CPU must read I2CSTA, clear the interrupt by writing to I2CCON, and issue a hardware RESET to restore full functionality - preventing indefinite bus hang.