NEW PRODUCT – 8-channel Bi-directional Level Converter – TXB0108
NEW PRODUCT – 8-channel Bi-directional Level Converter – TXB0108. 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/conversion 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 where this lovely chip, the TXB0108 bi-directional level converter comes in! 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). 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!
This breakout saves you from having to solder the very fine pitch packages that this chip comes with. We also add 0.1uF caps onto both sides and a 10K pull-down resistor on the output enable pin so you can use it right out of the box!
Adafruit publishes a wide range of writing and video content, including interviews and reporting on the maker market and the wider technology world. Our standards page is intended as a guide to best practices that Adafruit uses, as well as an outline of the ethical standards Adafruit aspires to. While Adafruit is not an independent journalistic institution, Adafruit strives to be a fair, informative, and positive voice within the community – check it out here: adafruit.com/editorialstandards
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.
Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7:30pm ET! To join, head over to YouTube and check out the show’s live chat and our Discord!
You mention that this chip does not work well for I2C.
I have also found that it does not work well with some servos, specifically a couple models of the GWS Nano servos. It has worked well with others.
You can get it to work with these servos by putting a resistor inline with the signal (to reduce the strength of the pullup that appears to be in the servo). I used a 10K 1/8W resistor because it was handy, but the ideal is supposed to be around 4.7K or 5.1K.
Note that you don’t need 5v to control these particular servos. I’ve gotten them to work with around 2.5v (I forget the exact lower limit in my test).
It’s just something else to consider when using these chips.
Woo hoo! Very nice indeed! Beats the usual ugly hacks
Merge this into an XBee shield and you’re rocking.
Data sheet is here.
http://pdf1.alldatasheet.com/datasheet-pdf/view/169210/TI/TXB0108.html
Great idea, and a cool chip. I’m curious if you’ll be providing breakout to the TXS0102, which is intended for applications like i2c/1-wire.
we will have the txs0102 shortly, we just got the prototype in and are testing it now (there is no ETA, however)
You mention that this chip does not work well for I2C.
I have also found that it does not work well with some servos, specifically a couple models of the GWS Nano servos. It has worked well with others.
You can get it to work with these servos by putting a resistor inline with the signal (to reduce the strength of the pullup that appears to be in the servo). I used a 10K 1/8W resistor because it was handy, but the ideal is supposed to be around 4.7K or 5.1K.
Note that you don’t need 5v to control these particular servos. I’ve gotten them to work with around 2.5v (I forget the exact lower limit in my test).
It’s just something else to consider when using these chips.