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. 74LS03 Quad 2-input NAND Gate contains four independent 2-input NAND gates. The open-collector outputs require pull-up resistors to perform correctly. They may be connected to other open-collector outputs to implement active-low wired-OR or active-high wired-AND functions. Open-collector devices are often used to generate higher VoH levels.
74LS03 Features
- Four Independent NAND Gates
- Open Collector Outputs Require Pull-Up Resistors
- Also Available in SMD Type
- Operating Temperature to 70°C
- Standard TTL Switching Voltages
74LS03 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 |
74LS03 Pinout Diagram
74LS03 Pin Description
| Pin No | Pin Name | Description |
| 1 | A1 | NAND Gate 1 Input 1 |
| 2 | B1 | NAND Gate 1 Input 2 |
| 3 | C1 | NAND Gate 1 Output |
| 4 | A2 | NAND Gate 2 Input 1 |
| 5 | B2 | NAND Gate 2 Input 2 |
| 6 | C2 | NAND Gate 2 Output |
| 7 | GND | Ground |
| 8 | C3 | NAND Gate 3 Output |
| 9 | A3 | NAND Gate 3 Input 1 |
| 10 | B3 | NAND Gate 3 Input 2 |
| 11 | C4 | NAND Gate 4 Output |
| 12 | A4 | NAND Gate 4 Input 1 |
| 13 | B4 | NAND Gate 4 Input 2 |
| 14 | VCC | Positive Supply |
74LS03 Circuit
Below is a simple NAND gate circuit implementation using diodes and one NPN transistor. You can use 1n4007 as diode and r1,r2 of 10k ohm, and bc547 general purpose transistor.
Applications
- Burglar alarm or theft alarm.
- Freezer warning buzzer.
- Light activated theft alarm.
- Automatic watering system
74LS03 Alternative Equivalent
74LS00, 74LS10, 74LS20, 74LS30
Download 74LS03 Quad 2-input NAND Gate from the link given below.
