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. 74LS74 contains two independent positive-edge-triggered D flip-flops with complementary outputs. The information on the D input is accepted by the flip-flops on the positive-going edge of the clock pulse.

74LS74 Features
- Two Independent Negative Edge Triggered JK Flip-Flops
- Standard Pin Arrangement
- Fast Switching Times
- Operating Temperature up to 70°C
- Standard TTL Switching Voltages
74LS74 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 |
74LS74 Pinout Diagram

74LS74 Pin Description
Pin No | Pin Name | Description |
1 | CD | Digital Clock Pin |
2 | D | Data Pin |
3 | CP | Clear Pin |
4 | SD | Set Data Pin |
5 | Q1 | Output Pin Q1 |
6 | Q1′ | Invert Output Pin Q1′ |
7 | GND | Ground |
8 | Q2′ | NAND Gate 4 Output 4 |
9 | Q2 | Invert Output Pin Q2′ |
10 | SD | Set Data Pin |
11 | CP | Clear Pin |
12 | D | Data Pin |
13 | CD | Digital Clock Pin |
14 | VCC | Positive Supply |
74LS74 Circuit
Applications
- Data Storage
- Counters & State Machine Designs
- Logic Synchronizing
- Divide By Circuits
74LS74 Alternative Equivalent
74LS174,74LS175
Download 74LS74 Dual D-Type Flip-Flop Datasheet from the link given below.