Inverter (logic gate)

A NOT gate (german: NOT gate), also referred to as complement- gate or inverter, a gate connected to an input and an output. It corresponds to the logical not. In SL, the complement by a ¬ is before represented in the Boolean algebra by a bar over the corresponding symbols.

It just then the output provides a 1 if the input is a 0 is present and if and 0 if a 1 is present at the input. So he returns the negation of the signal at the input signal.

Survey

The non-character (¬ ) is located in Unicode at position 00AC. On Windows machines, it can enter yourself by entering the number while holding the Alt key 0172.

Switching characters

There are several variations of the switch symbol: The American is a triangle with Squiggle, the European either a rectangle with the inscription "1" or a semi-circle with a squiggle or a black dot on input or output.

Electronic realization

A NOT gate, for example, on a bipolar switching transistor in the emitter circuit ( see picture left ) are based, of the output to ground (logic 0) shall, as soon as it is turned on. If he fails, the ground connection is interrupted and the output is through the working resistance of the emitter circuit to plus potential (logic 1).

In integrated circuits, non- gates are usually by means of CMOS logic, based on a p -channel and n- channel MOSFET, realized (see picture right).

Applications

Not gates are required for various applications. Two series-connected NOT gate may be used as a signal amplifier ( buffer).

Due to the principle in the CMOS technology, NAND gate or NOR gate (consisting of four transistors ) basic circuits; to obtain AND-OR gate, a NOT gate must be installed downstream of each.