July 15, 2011 AT 4:27 pm

PART FINDER FRIDAY – Bidirectional level shifters

Txb0108

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!

Read more in the PART FINDER


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4 Comments

  1. Do you have this chip in any of the items you sell?

  2. @rick – http://www.adafruit.com/products/395

  3. The Ideanator

    Will it do USB?

  4. Ideanator. that’s a good question! we have no idea. it can probably do USB low speed and maybe ‘standard’ speed but not high speed

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