BSS138 level shifter
One channel of the bi-directional 3.3 V to 5 V level shifter: a BSS138 and two 10k pull-ups. Pull either side low and the other follows. There is no microcontroller in it: the simulator solves the 7 parts as a circuit, so it runs the moment you press Run, and nothing needs compiling.
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The parts retail for about $5.90. On Mokxi they're free.
How it works
There is no microcontroller in this one, so nothing is compiled: the simulator solves the circuit itself. The file in the editor is the notes that come with it.
// One channel of a BSS138 level shifter. Left meter: the 3.3 V side (the
// source); right meter: the 5 V side (the drain); a 10k pull-up on each.
//
// Both switches open, each side sits at its own supply and the BSS138 is
// off. Pull the 3.3 V side low and the channel pulls the 5 V side down with
// it. Pull the 5 V side low instead: the body diode drags the source down
// until the channel turns on, so it works both ways.
Parts list
8 parts, plus the jumper wires and 2 bench instruments. The parts retail for about $5.90; on Mokxi they're free, and so are the instruments.
- 1 × Full-size breadboard
- 1 × Power, 3.3 V
- 1 × Power, 5 V
- 1 × MOSFET
- 2 × Resistor, 10k Ω
- 2 × Slide switch
- 2 × Multimeter
How it is wired
5 connections, pin by pin, read from the circuit itself. Each line is one set of pins joined together, by a jumper wire or a breadboard strip.
- 3.3 V: MOSFET pin G; Resistor, 10k Ω (1) pin 2
- 5 V: Resistor, 10k Ω (2) pin 1
- Ground: Slide switch (1) pin 3; Slide switch (2) pin 3; Multimeter (1) pin COM; Multimeter (2) pin COM
- MOSFET pin S; Resistor, 10k Ω (1) pin 1; Slide switch (1) pin 2; Multimeter (1) pin V
- MOSFET pin D; Resistor, 10k Ω (2) pin 2; Slide switch (2) pin 2; Multimeter (2) pin V
Change it and keep it
Open it in the editor, change the circuit or the code, and keep your version in a free account.