What is it?

This is an eight-channel logic level translator based on Texas Instruments' new LSF0108 bidirectional, multi-voltage level translator for open-drain and push-pull applications. The breakout board is breadboard friendly, as easy to use as less-expensive but less-capable alternatives, but offers several advantages over traditional MOSFET-based logic level translators. The LSF0108 has a very low (<30 Ohm, and only 9 Ohm when translating between 3V3 and 5V) on resistance, meaning that there is almost no voltage drop across the device (<0.1 V when translating between 3V3 and 5 V at <10 mA, for example I2C) so fast signal are not degraded during the translation. The LSF0108 is capable of translating very fast signals (>100 MHz) without degradation, and can handle multiple voltages in a single device. Lastly, the LSF0108 offers eight channels of translation. Eight is better than four!

Why did you make it?

The traditional logic level converters are great; I have many and have used them often. In one application I found that the 10K resistance on the translator caused a significant drop in the voltage of the PWM signal I was translating because the input impedance of the high side device was significantly lower than 10K. Also, when running PWM above 1 MHz I noticed quite a lot of degradation in the sharpness of the pulse edges. The final straw was when I had to add logic level translation circuitry to an adapter board for the Edison; all the MOSFETs and resistors really took up a lot of space. The LSF0108 is a beautiful solution to these kinds of problems. It is a very compact chip and only requires two passive components. More importantly, it is a very flexible solution that is designed to pass very fast signals without degradation and reduces voltage drops to almost nothing. This 0.6 in x 0.6 in board is about the same size as the traditional logic level converter, but it offers eight channels of translation. This comes in pretty handy if you ever have to translate an SPI port which requires MOSI, MISO, CLK, CE, and CS signals---more than four!

What makes it special?

This is brand new technology that offers significant advantages over the MOSFET + resistor logic level conversion solution most of use are used to. It is offered in an "appallingly small" breakout board with eight channels of translation for a very reasonable price. Order the board from OSH Park and assemble your own or buy one fully assembled and tested from me and see how much better modern logic level translators have become!