Level Shifting – Voltage Level Shifter Guide


I need to make a voltage level shifter. It needs to translate a TTL logic level into a 12 V logic level.

I have applied the 5 V at the base and 12 V Vcc and took the output from the collector (not using any emitter resistor). The output was good, but the current was 0 mA when Vcc was 12 V and the phase was shifted.

I've tried connecting the load at the emitter and the voltage was just 5 V or less.

How do I make such a voltage level translator?

Best Answer

Check out Sparkfun's Logic Level converter. It includes a schematic, you should be able to do almost exactly the same thing by hand, but you'll probably need to use different resistor values to get the correct voltages. It includes two circuits, one for connecting a low voltage transmitter to a high voltage receiver, and one for connecting a high voltage transmitter to a low voltage receiver. It sounds like the former is what you're asking for.