TCA9802 Level-Translating I2C Bus Buffer/Repeater

1 Features

• Two-channel bidirectional buffer
• Integrated current source on B-side, requires no external B-side resistors
• Ultra-low power consumption
• No static-voltage offset, low V_OL
• I²C bus and SMBus compatible
• Operating supply voltage range of 0.8 V to 3.6 V on A-side
• Operating supply voltage range of 1.65 V to 3.6 V on B-side
• Active-high repeater enable input
• Powered-off high impedance I²C bus pins on A-side
• Powered-off back-power protection I²C bus pins
• Support for clock stretching and multiple master arbitration
• Family of current source options from 0.5 mA to 3 mA

2 Applications

• Servers
• Routers (routing equipment)
• Industrial equipment
• Personal computers
• Power-sensitive applications

3 Description

The TCA9802 is a dual-channel bidirectional buffer intended for I²C bus and SMBus/PMBus systems. It provides bidirectional level shifting (up-translation and down-translation) between low voltages (down to 0.8 V) and higher voltages (1.65 V to 3.6 V). The TCA9802 features an internal current source on the B-side of the device, allowing the removal of external pull-up resistors on the B-side. The current source also provides an improved rise time and ultra-low power consumption.

The TCA9802 is able to provide true buffering (rather than a pass-FET solution) without using a static voltage offset or incremental offset. This means that the V_OL on both the A and B sides of the TCA9802 are very low (approximately 0.2 V), helping to eliminate communication issues as a result of fixed V_IL thresholds. Another key feature of the TCA9802 is that there are no power sequencing requirements, or power supply dependencies. V_CCA can be greater than, less than, or equal to V_CCB. This gives the system designer flexibility with how the TCA9802 is used.

The TCA9802 is part of a four device family with varying current source strengths (see the Device Comparison Table).

1. For all available packages, see the orderable addendum at the end of the data sheet.

Device Images

Simplified Schematic