1. IC Packages

2. 2 Integration SSI  Small-Scale Integration −Several gates in a package MSI  Medium-Scale Integration −Tens of gates in a package LSI  Large-Scale Integration −Hundreds to hundred thousands of gates in a package VLSI  Very Large-Scale Integration −More than above −E.g. Microprocessors.

3. 3 SSI (7400 Series)

4. 4 DIP Dual in-line Packages

5. 5 Tri-State (Output Enable) Gate Tri-State (Three-State) Inverter:  The output in NOT of input if the Enable input is HIGH  Else Hi-Impedance (Hi-Z) −Unconnected. Enable input output input Enable Tri-State (Three-State) Buffer:

6. 6 Active Low Input Tri-State Buffer with Active Low Enable: Tri-State Inverter with Active Low Enable: in out EN in out EN 3-state BUF, EN low 3-state INV, EN low