The AND gate is an electronic circuit that gives a high output
(1) only if all its inputs are high. A dot (.) is used to show
the AND operation i.e. A.B. Bear in mind that this dot is
sometimes omitted i.e. AB. "If both Inputs are true the Output
will be true" 3 Input AND gate Truth table : TTL AND gate : TTL
Logic gates are constructed by Transistor-Transistor Logic.
Fig-2 shows a RTL- Resistor Transistor Logic. The TTL based AND
gate ICs are as below : - 74LS08 Quad 2-input - 74LS11 Triple
3-input - 74LS21 Dual 4-input CMOS AND gate : Three(3) p-type
and three(3) n-type MOSFETs constructs a 2 input AND gate logic.
The first 2 p-type and 2 n-type MOSFET construct a NAND gate
logic and the rest two p-type and n-type construct an Inverter
logic. So the first portion gives NAND output and the second
part getting that output gives AND output doing the NOT logic
operation (inverting) see the Fig-3. The CMOS type AND gates are
shown below : - CD4081 Quad 2-input - CD4073 Triple 3-input -
CD4082 Dual 4-input AND ga