The TCA9548A-Q1 device has eight bidirectional translating switches that can be controlled through the I 2C bus. The SCL/SDA upstream pair fans out to eight downstream pairs, or channels. Any individual SCn/SDn channel or combination of channels can be selected, determined by the contents of the programmable control register. These downstream channels can be used to resolve I 2C target address conflicts. For example, if eight identical digital temperature sensors are needed in the application, one sensor can be connected at each channel: 0-7.
The system controller can reset the TCA9548A-Q1 in the event of a time-out or other improper operation by asserting a low in the RESET input. Similarly, the power-on reset deselects all channels and initializes the I 2C/SMBus state machine. Asserting RESET causes the same reset and initialization to occur without powering down the part. This allows recovery should one of the downstream I 2C buses get stuck in a low state.
The pass gates of the switches are constructed so that the VCC pin can be used to limit the maximum high voltage, which is passed by the TCA9548A-Q1. Limiting the maximum high voltage allows the use of different bus voltages on each pair, so that 1.8 V, 2.5 V or 3.3 V parts can communicate with 5 V parts, without any additional protection. External pull-up resistors pull the bus up to the desired voltage level for each channel. All I/O pins are 5 V tolerant.
| Top documentation | Type | Title | Format options | Date |
|---|---|---|---|---|
| * | Data sheet | TCA9548A-Q1 Automotive 8-Channel I2C Switch with Reset datasheet (Rev. C) | PDF | HTML | Jun 9, 2023 |
| Application note | I2C Solutions for Hot Swap Applications (Rev. A) | Jan 31, 2023 | ||
| Functional safety information | TCA9548A-Q1 Functional Safety, FIT Rate, Failure Mode Distribution and Pin FMA | PDF | HTML | Feb 22, 2021 |
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The TCA9548AEVM is designed to evaluate and demonstrate the functionality of TI’s TCA954xA family of I2C switches. The TCA9548AEVM can be used as a standalone evaluation module to interface with an existing system or paired with the MSP430 Lauchpad which serves as the I2C master and power supply (...)
| Package | Pins | CAD symbols, footprints & 3D models |
|---|---|---|
| VQFN (RGE) | 24 | Ultra Librarian |
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