The 74LS21 IC package contains two independent positive logic 4-input AND Gates, belonging to the 74XXYY TTL IC series. The 74LS21 IC has a wide range of working voltage, a wide range of working conditions, and directly interfaces with CMOS, NMOS, and TTL. The output of the IC always comes in TTL which makes it easy to work with other TTL devices and microcontrollers. The IC 74LS21 is smaller in size and it has a much faster speed which makes it reliable in every kind of device.
What is an AND Gate?
An AND Gate is a logical operator/circuit that gives a logical high (1) output only when all of its inputs are high (1), otherwise, it results in a logical low (0). The logic or Boolean expression for a digital logic AND gate is that for Logical Multiplication which is denoted by a single dot or full stop symbol ( . ).
74LS21 Pinout
74LS21 Pin Configuration
| Pin No | Pin Name | Description |
|---|---|---|
| 1 | A1 | INPUT 1 of GATE 1 |
| 2 | B1 | INPUT 2 of GATE 1 |
| 3 | NC | No Connection |
| 4 | C1 | INPUT 3 of GATE 1 |
| 5 | D1 | INPUT 4 of GATE 1 |
| 6 | Q1 | OUTPUT of GATE 1 |
| 7 | GND | Ground Pin |
| 8 | Q2 | OUTPUT of GATE 2 |
| 9 | A2 | INPUT 1 of GATE 2 |
| 10 | B2 | INPUT 2 of GATE 2 |
| 11 | NC | No Connection |
| 12 | C2 | INPUT 3 of GATE 2 |
| 13 | D2 | INPUT 4 of GATE 2 |
| 14 | VCC | Supply Voltage |
74LS21 Features & Specifications
- Input Voltage: 7V
- Max supply voltage: 7V
- Max current allowed to draw through each gate output: 8mA
- TTL outputs
- Low power consumption
- Typical Rise Time: 18ns
- Typical Fall Time: 18ns
- Operating temperature: 0°C to +70°C
- Storage Temperature: -65°C to +150°C
Applications
- Microprocessor Interfacing in devices such as PCs, Notebooks, mobiles, etc.
- The chip provides TTL outputs that are needed in some systems.
You can download this Datasheet 74LS21 Dual 4-input AND Gate from the link given below:
See Also: 74LS10 Triple 3-Input NAND IC | 74LS20 Dual 4 – Input NAND IC | 7407 Hex Buffer IC
