Click here to purchase one from the Adafruit shop
This is lovely chip: the TXB0104 bi-directional level converter! This chip perform bidirectional level shifting from pretty much any voltage to any voltage and will auto-detect the direction. Only thing that doesn't work well with this chip is i2c (because it uses strong pullups which confuse auto-direction sensor) or control lines with a lot of capacitance on them. If you need to use pullups, you can but they should be at least 50K ohm - the ones internal to AVRs/Arduino are about 100K ohm so those are OK! Its a little more luxurious than a 74LVX245 but if you just don't want to worry about directional pins this is a life saver!
Since this chip is a special bi-directional level shifter it does not have strong output pins that can drive LEDs or long cables, it's meant to sit on a breadboard between two logic chips! If you do not need instant bi-directional support, we suggest the 74LVX245 as below which has stronger output drive.
PCB files for the Adafruit TXB0104 Level Shifter Breakout. The format is EagleCAD schematic and board layout
Adafruit invests time and resources providing this open source design, please support Adafruit and open-source hardware by purchasing products from Adafruit!
All text above must be included in any redistribution
Designed by Limor Fried/Ladyada for Adafruit Industries. Creative Commons Attribution/Share-Alike, all text above must be included in any redistribution. See license.txt for additional information.