The TTL family uses the NAND gate,the ECL family uses the NOR gate and the CMOS family uses the inverter.

• 晶体管-晶体管逻辑电路元件应用NAND栅门，发射极耦合逻辑电路元件应用NOR栅门，补充金属氧化物半导体元件使用变极器。