Definition: What is a Level Shifter?
A level shifter, or logic-level shifter, is a circuit used to translate signals from one logic level or voltage domain to another. This allows compatibility between integrated circuits which operate at different voltages or have different voltage requirements, such as TTL and CMOS. Many modern devices use level shifters to translate voltage levels or bridge voltage domains between processors, sensors, logic integrated circuits, and other circuits. The most common logic level voltages currently are 1.8-Volts, 3.3-Volts, and 5-Volts.
Level shifters can have a couple different configurations. There are uni-directional level shifters which can only shift voltage levels in a single direction, such as 3.3-Volts being translated to 5-Volts, but not the reverse. Other level shifters, such as those supplied in Tech-Box.io kits, are bi-directional, meaning that voltage can be translated both from a lower voltage to a higher voltage, and vice versa. Some level shifters do not work at all of the common voltage levels however, so be sure to use the ones supplied in your Tech-Box.io kits when completing your kit's construction.