PART FINDER FRIDAY – Bidirectional level shifters. Because the Arduino (and Basic Stamp) are 5V devices, and most modern sensors, displays, flash cards and modes are 3.3V-only, many makers find that they need to perform level shifting to protect the 3.3V device from 5V. Although one can use resistors to make a divider, for high speed transfers, the resistors can add a lot of slew and cause havoc that is tough to debug. For that reason, we like using 4050/74LVX245 series and similar logic to perform proper level shifting. Only problem is that they are only good in one direction which can be a problem for some specialty bi-diectional interfaces and also makes wiring a little hairy.
That’s why we dig the TXB0108 (and friends) level shifters. These guys perform bidirectional level shifting from pretty much any voltage to any voltage and auto-detect the direction. Only thing that doesn’t work here is i2c (because it uses pullups which confuse the chip). 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!
Comes only in SMT format, the TSSOP is most friendly to solder. We even have it in our Eagle library for immediate use!