The 74LS series of integrated circuits (ICs) was one of the most popular logic families of transistor-transistor logic (TTL) logic chips. 74LS series is a bipolar, low-power Schottky IC. 74LS40 contain DUAL 4-INPUT NAND BUFFER
74LS40 Features
- Two Independent NAND Buffer Gates
- Open Collector Outputs Require External Pull-Up Resistors
- Fast Switching Times
- Operating Temperature up to 70°C
- Standard TTL Switching Voltages
74LS40 Specifications
| Supply Voltage | 4.75 – 5.25Vdc |
| Maximum Clock Frequency | 40Mhz |
| Power Dissipation | 2mW/gate @100kHz |
| Minimum Output Current | 8mA |
| Propagation Delay | 10nS |
| Fan Out (TTL Loads) | 20 |
74LS40 Pinout Diagram
74LS40 Pin Description
| Pin No | Pin Name | Description |
| 1 | A1 | NAND Buffer 1 Input 1 |
| 2 | B1 | NAND Buffer 1 Input 2 |
| 3 | NC | No Connection |
| 4 | C1 | NAND Buffer 1 Input 3 |
| 5 | D1 | NAND Buffer 1 Input 4 |
| 6 | X1 | NAND Buffer 1 Output |
| 7 | GND | Ground |
| 8 | X2 | NAND Buffer 2 Output |
| 9 | A2 | NAND Buffer 2 Input 1 |
| 10 | B2 | NAND Buffer 2 Input 2 |
| 11 | NC | No Connection |
| 12 | C2 | NAND Buffer 2 Input 3 |
| 13 | D2 | NAND Buffer 2 Input 4 |
| 14 | VCC | Positive Supply |
74LS40 Circuit
Applications
- Burglar alarm
- Freezer warning buzzer
74LS40 Alternative Equivalent
74LS37, 74LS30
Download 74LS40 DUAL 4-INPUT NAND BUFFER Datasheet from the link given below.
