Product Overview: PCA9544D from NXP

The PCA9544D is a robust, high-performance 4-channel I²C-bus switch with interrupt logic, manufactured by NXP Semiconductors. This integrated circuit is designed to provide seamless communication between a primary I²C-bus and multiple downstream channels, each of which can be active or inactive as determined by the user. This flexibility allows for expanded I²C system capabilities and helps in managing I²C address conflicts between devices that are otherwise incompatible.

Key Features

• Multi-Channel I²C Switching: The PCA9544D enables up to four downstream channels to be selected via the I²C-bus, making it ideal for applications that require multiple I²C devices with the same address to be connected to a single I²C-bus.
• Interrupt Functionality: Each channel can be associated with an interrupt signal, allowing the master device to be alerted when a condition on any of the slave devices has changed, without the need for constant polling.
• Low Standby Current: Designed with energy efficiency in mind, the PCA9544D maintains a low standby current, which is crucial for battery-powered and energy-sensitive applications.
• Active-Low Reset Input: An active-low reset input allows the PCA9544D to be reset by the system, ensuring reliable operation and recovery from fault conditions.

Applications

The PCA9544D is versatile and can be used in a variety of applications, including but not limited to:

• Server systems and data centers where multiple I²C devices are present.
• Industrial control systems requiring complex sensor arrays.
• Consumer electronics that house multiple I²C-compatible components.
• Telecommunications equipment that demands high-speed I²C communications.

Technical Specifications

The device operates over a supply voltage range of 2.3V to 5.5V and is available in a 20-pin TSSOP package. It features an operating frequency of up to 400 kHz (Fast-mode I²C) and is fully compliant with the I²C-bus specification. Additionally, the PCA9544D offers an active LOW reset input and incorporates an active LOW interrupt input for each of the four connected slave devices.