TXS0108E 8-Channel Bi-Directional Logic Level Converter Module – Support Documentation
The TXS0108E is an 8-bit, bi-directional logic level translator designed for open-drain and push-pull applications. It enables seamless communication between devices operating at different voltage levels, such as 1.2V, 1.8V, 3.3V, and 5V systems.
Key Features
- Bi-directional voltage-level translation without the need for a direction-control signal.
- Supports both open-drain and push-pull applications.
- Maximum data rates:
- 110 Mbps for push-pull applications.
- 1.2 Mbps for open-drain applications.
- Wide voltage range:
- VCCA: 1.2V to 3.6V.
- VCCB: 1.65V to 5.5V.
- No power-supply sequencing required; VCCA or VCCB can be ramped first.
- Low power consumption with automatic direction sensing.
- Compact module size: approximately 26mm x 16mm x 3mm.
Pinout
| Pin | Name | Function |
|---|---|---|
| 1 | VCCA | Low voltage side supply input (1.2V to 3.6V). |
| 2 | A1 | Channel 1 low voltage side I/O. |
| 3 | A2 | Channel 2 low voltage side I/O. |
| 4 | A3 | Channel 3 low voltage side I/O. |
| 5 | A4 | Channel 4 low voltage side I/O. |
| 6 | A5 | Channel 5 low voltage side I/O. |
| 7 | A6 | Channel 6 low voltage side I/O. |
| 8 | A7 | Channel 7 low voltage side I/O. |
| 9 | A8 | Channel 8 low voltage side I/O. |
| 10 | OE | Output Enable (active high). Enables outputs when high; places all outputs in high-impedance state when low. |
| 11 | GND | Ground. |
| 12 | B8 | Channel 8 high voltage side I/O. |
| 13 | B7 | Channel 7 high voltage side I/O. |
| 14 | B6 | Channel 6 high voltage side I/O. |
| 15 | B5 | Channel 5 high voltage side I/O. |
| 16 | B4 | Channel 4 high voltage side I/O. |
| 17 | B3 | Channel 3 high voltage side I/O. |
| 18 | B2 | Channel 2 high voltage side I/O. |
| 19 | B1 | Channel 1 high voltage side I/O. |
| 20 | VCCB | High voltage side supply input (1.65V to 5.5V). |
How to Use the TXS0108E Module
- Power Connections:
- Connect VCCA to the lower voltage logic level (e.g., 3.3V).
- Connect VCCB to the higher voltage logic level (e.g., 5V).
- Ensure both systems share a common ground (GND).
- Data Connections:
- Connect the lower voltage device’s I/O pins to A1–A8.
- Connect the higher voltage device’s I/O pins to B1–B8.
- Output Enable (OE):
- To enable the translator, tie OE high (to VCCA).
- To disable and place all outputs in high-impedance state, tie OE low (to GND).
Example Application
Connecting a 3.3V microcontroller (e.g., Raspberry Pi) to a 5V peripheral (e.g., Arduino):
- Connect Raspberry Pi’s 3.3V supply to VCCA.
- Connect Arduino’s 5V supply to VCCB.
- Connect Raspberry Pi’s GPIO pins to A1–A8 as needed.
- Connect Arduino’s corresponding pins to B1–B8.
- Ensure both devices share a common ground.
- Tie OE to VCCA to enable the translator.
Troubleshooting
- No Signal Translation: Verify that OE is tied high to enable the translator.
- Communication Errors: Ensure that VCCA and VCCB are supplied with the correct voltages corresponding to the connected devices.
- Unstable Operation: Check for proper grounding between all devices and ensure that the supply voltages are within specified ranges.
Frequently Asked Questions
Can I use the TXS0108E for I2C communication?
Yes, the TXS0108E supports open-drain applications like I2C. Ensure that appropriate pull-up resistors are used on both sides of the translator.
Is a direction-control signal required?
No, the TXS0108E features automatic direction sensing and does not require a direction-control signal.
What happens if OE is left floating?
If OE is left floating, the behavior is undefined. It is recommended to tie OE high to enable the translator or low to disable it.
Can I connect multiple channels simultaneously?
Yes, all eight channels can be used simultaneously for bi-directional level translation.
Conclusion
The TXS0108E 8-Channel Bi-Directional Logic Level Converter Module is a versatile solution for interfacing devices operating at different voltage levels. Its automatic direction sensing and wide voltage range make it suitable for various applications, including communication between microcontrollers, sensors, and peripherals.