
Texas Instruments TCA9803 Bus Buffer/Repeater
Texas Instruments TCA9803 Bus Buffer/Repeater is a dual-channel bidirectional buffer intended for I2C bus and SMBus/PMBus systems. The device provides bi-directional level shifting between low voltages (down to 0.8V) and higher voltages (1.65V to 3.6V). The TCA9803 features an internal current source on the B-side of the device. This feature allows 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 Texas Instruments TCA9803 can provide true buffering (rather than a pass-FET solution) without a static voltage offset or incremental offset. This feature means that the VOL on both the A and B sides of the TCA9803 is very low. This feature helps to eliminate communication issues due to fixed VIL thresholds. Another key component of the TCA9803 is there are no power sequencing requirements or power supply dependencies. The VCCA can be greater than, less than, or equal to VCCB. This additional feature gives the system designer flexibility with how the TCA9803 is used.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 VOL
- I2C bus and SMBus compatible
- Operating supply voltage range of 0.8V to 3.6V on the A-side
- Operating supply voltage range of 1.65V to 3.6V on the B-side
- Active-high repeater enable input
- Powered-off high impedance I2C bus pins on the A-side
- Powered-off back-power protection I2C bus pins
- Support for clock stretching and multiple master arbitration
- Family of current source options from 0.5mA to 3mA
Applications
- Servers
- Routers (routing equipment)
- Industrial equipment
- Personal computers
- Power-sensitive applications
Simplified Schematic

Published: 2017-04-26
| Updated: 2022-04-27