SparkFun Single Supply Logic Converter
The SparkFun Single Supply Logic Level Converter is logic level and power supply translator in one small package. This little board breaks out the Texas Instruments TXB0104 4-bit bi-directional voltage-level translator with automatic direction sensing. With this logic level converter you will be able to use your 5V logic microcontroller with 3.3V sensors without the second power supply!
What makes this Logic level converter truly special is the fact that you can supply it with 3.3V and it will create the 5V - meaning you can use your 3.3V system, and convert directly to another 5V sensor - and even power your sensor or other board!
This logic level converter provides 5V to the high side of the TXB0104 and the low side is programmable to 3.3V, 2.5V and 1.8V. Please keep in mind that the default low side voltage is 3.3V.