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In digital logic, an inverter or NOT gate is a logic gate which implements logical negation. The truth table is shown on the right. ==Electronic implementation== Image:NMOS NOT.svg|NMOS inverter Image:PMOS NOT.png|PMOS inverter Image:CMOS Inverter.svg|Static CMOS inverter Image:Puertas NOT con transistores.jpg|NPN transistor–transistor logic inverter Image:Nmos depletion and.svg|Depletion-load NMOS logic NAND Image:DigitalInverter.png|Saturated-load NMOS inverter Image:Transistor pegelumsetzer.svg|NPN resistor–transistor logic inverter An inverter circuit outputs a voltage representing the opposite logic-level to its input. Its main function is to invert the input signal applied. If the applied input is low then the output becomes high and vice versa. Inverters can be constructed using a single NMOS transistor or a single PMOS transistor coupled with a resistor. Since this 'resistive-drain' approach uses only a single type of transistor, it can be fabricated at low cost. However, because current flows through the resistor in one of the two states, the resistive-drain configuration is disadvantaged for power consumption and processing speed. Alternatively, inverters can be constructed using two complementary transistors in a CMOS configuration. This configuration greatly reduces power consumption since one of the transistors is always off in both logic states. Processing speed can also be improved due to the relatively low resistance compared to the NMOS-only or PMOS-only type devices. Inverters can also be constructed with bipolar junction transistors (BJT) in either a resistor–transistor logic (RTL) or a transistor–transistor logic (TTL) configuration. Digital electronics circuits operate at fixed voltage levels corresponding to a logical 0 or 1 (see binary). An inverter circuit serves as the basic logic gate to swap between those two voltage levels. Implementation determines the actual voltage, but common levels include (0, +5V) for TTL circuits. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Inverter (logic gate)」の詳細全文を読む スポンサード リンク
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