The PCA9509D is an I2C-bus extender/hub that enables the extension of the I2C-bus by providing voltage level translation and buffering capabilities. It allows for connecting multiple I2C devices with different voltage levels and drive strengths, facilitating communication between them.

Applications

• I2C bus extension
• Voltage level translation
• Multi-master I2C systems
• Isolated I2C communication
• Systems with mixed voltage I2C devices

Features

• I2C-bus repeater/hub
• Voltage level translation: 1.0 V to 5.5 V
• Bidirectional buffer with active pull-up
• Supports Standard-mode, Fast-mode, and Fast-mode Plus I2C-bus speeds
• Low standby current
• Hot insertion

Benefits

• Extends the reach of the I2C-bus, enabling communication over longer distances.
• Allows for seamless integration of I2C devices with different voltage levels.
• Improves signal integrity in noisy environments.
• Simplifies the design of complex I2C systems.
• Minimizes power consumption in standby mode.

Additional Details

The PCA9509D incorporates bidirectional buffers with active pull-ups on both the upstream and downstream I2C ports, providing improved signal drive and noise immunity. The voltage level translation feature allows for connecting I2C devices operating at different voltage levels without the need for external level shifters. This simplifies the system design and reduces component count. The device supports Standard-mode (100 kHz), Fast-mode (400 kHz), and Fast-mode Plus (1 MHz) I2C-bus speeds, making it compatible with a wide range of I2C devices. The hot insertion capability allows for connecting or disconnecting I2C devices while the system is powered on, without causing disruptions. Its low standby current helps to minimize power consumption in battery-powered applications.