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. 74LS12 3-INPUT NAND GATE (OPEN COLLECTOR) containing three independent 3-input NAND gates with open-collector outputs. 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.
74LS12 Features
- Three Independent NAND Gates
- Standard Pin Configuration
- Fast Switching Times
- Operating Temperature up to 70°C
- Standard TTL Switching Voltages
74LS12 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 |
74LS12 Pinout Diagram
74LS12 Pin Description
| Pin No | Pin Name | Description |
| 1 | A1 | NAND Gate 1 Input 1 |
| 2 | B1 | NAND Gate 1 Input 2 |
| 3 | A2 | NAND Gate 2 Input 1 |
| 4 | B2 | NAND Gate 2 Input 2 |
| 5 | C2 | NAND Gate 2 Input 3 |
| 6 | D2 | NAND Gate 2 Output |
| 7 | GND | Ground |
| 8 | D3 | NAND Gate 3 Output |
| 9 | A3 | NAND Gate 3 Input 1 |
| 10 | B3 | NAND Gate 3 Input 2 |
| 11 | C3 | NAND Gate 3 Input 3 |
| 12 | D1 | NAND Gate 1 Output |
| 13 | C1 | NAND Gate 1 Input 3 |
| 14 | VCC | Positive Supply |
74LS12 Circuit
Applications
- LDR
- Freezer warning buzzer circuits
- Automatic temperature control circuits
74LS12 Alternative Equivalent
74LS03, 74LS10,74LS01
Download 74LS12 3-INPUT NAND GATE (OPEN COLLECTOR) Datasheet from the link given below.
