- 8 channels can convert up to 8 logic signals
- Converts voltage levels between 1.2 to 3.6V and 1.65 to 5.5V systems
- Bi-directional with automatic direction control
- Each channel operates independently
- Optimized for open-drain applications like I2C, but can also work in push-pull applications
- Output enable allows outputs to be disabled
This module is typically used to connect 3.3V and 5V logic signals together, but it is compatible with many different logic voltages. The low (A) side can handle 1.2 to 3.6V logic levels. The high (B) side can handle 1.65 to 5.5V logic levels.
VCCA terminal support voltage : 1.2V-3.6V
VCCB terminal support voltage : 1.65V-5.5V
There are 8 bi-directional channels which is especially useful for buses that pass data in both directions. It can also be used for unidirectional signals like SPI.
The TXS0108 is designed for open-drain applications like I2C and includes dynamic pull-up / pull-down resistors, but it can be used in standard CMOS push-pull translation as well.
The output enable (OE) can be tied to Vcca to enable the outputs at all times. If it is desirable to have the device power up with the outputs disabled, use a pull-down resistor to ground which keeps the outputs off until it is enabled by driving the pin HIGH under uC control. Disabling the OE is also useful for ultra low power applications since it shuts off the pull-up resistors and drops the idle current to a few uA.
When hooking up power, the lower voltage side must be connected to the ‘A’ side. This will typically be 3.3V. The higher voltage side which is typically 5V should be connected to the ‘B’ side.
The device is not affected by power supply sequencing during power up, so having one side powered and the other side unpowered will not damage the device.