The TXB0104 is a 4-bit bidirectional voltage-level translator with automatic direction sensing. This is a module by Sparkfun based on the Texas Instruments TXB0104 powerful chip.
A lot of modern sensors, displays, flash cards and modes are 3.3V-only. On the other hand, Arduino and Basic Stamp are 5V devices. In that case you need to perform level shifting/conversion to protect the 3.3V device from 5V.
The TXB0104 features four channels of input/output signals and an output enable line that allows the signal lines to be placed in a high impedance mode when they are unneeded. This allows for universal low-voltage bidirectional translation between any of the 1.2-V, 1.5-V, 1.8-V, 2.5-V, 3.3-V, and 5-V voltage nodes. VCCA should not exceed VCCB.
- 1.2V to 3.6V on A Port and 1.65V to 5.5V on B Port (VCCA ≤ VCCB)
- VCC Isolation Feature – If Either VCC Input Is at GND, All Outputs Are in the High-Impedance State/A
- OE Input Circuit Referenced to VCC/A
- Low Power Consumption, 5-μA Max ICC/A