Logic Gate Families Introduction

Digital circuits make use of digital logic gates such as NAND and NOR for performing logic functions. These logic gates are manufactured using semiconductor devices. Depending on the device used for their construction, logic gates are classified as:

1. Diode Logic (DL) gates.
2. Diode-Transistor Logic (DTL) gates.
3. Transistor-Transistor Logic (TTL) gates.
4. N-type Metal-Oxide Semiconductor (NMOS) Logic gates.
5. Complementary MOS (CMOS) Logic gates.
6. Emitter-Coupled Logic (ECL) gates.
7. Integrated-Injection Logic (I2L) gates.

These logic-gate families generally belong to either the positive logic or the negative logic scheme.