SparkFun’s Logic Level Converter

SparkFun has always been good about designing and stocking useful breakout boards. This recently added Logic Level Converter is no exception. It’s uses two BSS138 MOSFETs to shift 5V logic levels to 3.3V. The board handles two separate serial pairs. Just hook up the RX and TX on either side. Provide power at both voltages and the board will happily do the conversion. It’s $2, smaller than the size of a quarter, and perfect for plugging into a breadboard.

10 thoughts on “SparkFun’s Logic Level Converter

  1. Hmmmn…at the expense of just 1 extra 10K resistor, they could have done 5V -> 3.3V conversion pretty much exactly.
    Adding another 10K in parallel with the top 10K resistor in the potential divider would give the output ratio 10/(10+5) = 2/3. So 5V input would then give 3.33333V out. They claim it also works with 2.8V -> 1.8V conversion. This extra resistor would then give 1.866666V out. Way closer than the 2.5V and 1.6V their design gives out.

  2. umm … commercial product. no real hack here. i’ll let it slide this time. i like to run my mixed voltage components directly off 3.7 volt lipos. or 5v with some resistors on the 3.3v side. sure it’s “wrong”, but it works for me. i’m not a properly edumacated electricioman, i’m a hacker!

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