74LS74

74LS74 replacement chip.  DIP-14, Dual D Type E positive-edge triggered flip-flops with preset and clear.

The 74LS74 is a popular integrated circuit (IC) that belongs to the TTL (Transistor-Transistor Logic) family. It is a dual D-type flip-flop, meaning it contains two separate flip-flops in a single package. The 74LS74 is widely used in digital electronics for various applications, including sequential logic and data storage.

Here are some key features and details about the 74LS74:

1. Flip-Flop Type:
   • The 74LS74 consists of two independent D-type positive-edge-triggered flip-flops. The D-type flip-flop is a basic building block in digital circuits, and it stores a single bit of data.
2. Triggering Edge:
   • The flip-flops in the 74LS74 are triggered on the positive edge of the clock signal. This means that the data input (D) is sampled and transferred to the output on the rising edge of the clock signal.
3. Inputs:
   • It has three main inputs for each flip-flop:
     • D (Data Input): The input to which the data to be stored is applied.
     • CLK (Clock Input): The clock signal that controls the timing of the flip-flop.
     • CLR (Clear): An active-low clear input that resets the flip-flop to its initial state.
4. Outputs:
   • Q and Q’ (Q-bar): These are the complementary outputs of each flip-flop. The state of the flip-flop is reflected in these outputs.
5. Power Supply:
   • The typical power supply voltage for the 74LS74 is in the range of 4.75V to 5.25V.
6. Package:
   • The 74LS74 is available in various packages, such as DIP (Dual Inline Package) and SOIC (Small Outline Integrated Circuit).
7. Applications:
   • The 74LS74 is commonly used in digital systems for tasks such as frequency dividers, shift registers, counters, and other sequential logic applications.

When using the 74LS74, it’s important to consider the specific datasheet for the device, as it provides detailed information on electrical characteristics, timing diagrams, and recommended operating conditions. The information provided here is a general overview, and actual usage may vary depending on the specific requirements of your circuit.

Arcade Games and Pinball Machines that Use 74LS74

The following arcade games and pinball machines use the 74LS74 on their PCBs:

• 1943
• Arkanoid
• Bubble Bobble
• Burgertime
• Centipede
• Donkey Kong
• Galaxian
• Gyruss
• Joust
• Jr. Pac-Man
• Macross
• Major Havok
• Moon Patrol
• Mortal Kombat 2
• Ms. Pac-Man
• Pac-Man
• Paperboy
• Phoenix
• Pole Position 1/2
• Red Barron
• Robotron
• Sea Wolf
• Tempest
• Time Soldier
• many others…

74LS74 / 74LS74N Pinout

The following represents the pinout of the 74LS74N in a DIP-14 package, commonly used in arcade and pinball machines.

• PIN 1: Clear Data
• PIN 2: Data Input 1
• PIN 3: Clock Input 1
• PIN 4: PRE Input 1
• PIN 5: Q1 Output
• PIN 6: Q1 Inverted Output
• PIN 7: Ground
• PIN 8: Q2 Inverted Output
• PIN 9: Load
• PIN 10: PRE Input 2
• PIN 11: Clock Input 2
• PIN 12: Data Input 2
• PIN 13: Clear Data
• PIN 14: Vcc

74LS74 Datasheet

You can find the datasheet for the 74LS74 here: 74LS74 datasheet