So we’ve explored the world of logic-level outputs, exposed a pitfall that we’d fallen into, and ended up revealing an unexpected feature of a popular board.

This is a simple and reliable circuit, but it must be borne in mind that it inverts the 3.3V logic level. Bi-directional level shifters The bidirectional MOSFET level shifter.

The single-supply level shifter (References 1 and 2) is shown in Figure 7. The main idea of this design is to recover the lower supply level from the input logic signal itself then used in the circuit ...