Description

The 74195 4-Bit Parallel-Access Shift Register is a versatile TTL logic IC designed for data storage, transfer, and manipulation in digital systems. This IC combines parallel loading and serial shifting capabilities, allowing users to load 4-bit data simultaneously or shift data bit by bit, either left or right. Housed in a 16-pin Dual Inline Package (DIP), the 74195 is ideal for digital electronics, microcontroller projects, display control, and data processing applications.

Shift registers like the 74195 are essential in serial-to-parallel and parallel-to-serial conversions, expanding the input/output capability of microcontrollers or digital systems while reducing the number of required I/O pins. Its synchronous design ensures all flip-flops respond simultaneously to clock pulses, providing precise, high-speed operation.

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⚙️ Key Features:

• Function: 4-bit parallel-access shift register with bidirectional shifting

• Logic Family: TTL (Transistor-Transistor Logic)

• Inputs: Parallel data inputs (D0–D3), serial inputs (A, B), shift/load control, clock input, clear

• Outputs: 4-bit outputs (Q0–Q3)

• Bidirectional Shift: Shift data left or right as needed

• Parallel Load: Load all 4 bits simultaneously for fast data entry

• Synchronous Operation: All flip-flops triggered by the same clock pulse

• Standard 16-Pin DIP Package: Suitable for breadboards and PCB designs

• Operating Voltage: 4.75V–5.25V (TTL standard)

• Low Power Consumption: Efficient and reliable

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🧩 Pin Configuration (16-Pin DIP):

This pinout allows flexible data manipulation, enabling parallel loading, serial shifting, and bidirectional data transfer.

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⚡ Electrical Characteristics:

• Supply Voltage (VCC): 5V TTL standard

• Input High Voltage (VIH): ≥ 2V

• Input Low Voltage (VIL): ≤ 0.8V

• Output High Voltage (VOH): ≥ 2.4V

• Output Low Voltage (VOL): ≤ 0.4V

• Propagation Delay: ~25 ns typical

• Power Dissipation: ~50 mW

Synchronous operation ensures high-speed data transfer and minimal propagation delay, making it suitable for real-time digital systems.

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🧠 How It Works:

The 74195 shift register allows data to be:

1. Loaded in Parallel: The 4-bit input (D0–D3) can be loaded simultaneously into the register when the load control is active.

2. Shifted Serially: Data can be shifted left or right one bit per clock pulse using serial inputs (A for right, B for left) controlled by shift inputs (S0, S1).

3. Cleared: The master reset (MR) resets all outputs to zero synchronously with the next clock pulse.

This combination of parallel and serial capabilities makes the 74195 ideal for flexible data handling in both simple and complex digital systems.

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🛠️ Applications:

• Microcontroller I/O Expansion – Increase input/output pins using serial-to-parallel conversion

• LED Display Control – Shift data to drive multiple segments or LED matrices

• Digital Data Storage – Temporary data storage for processing

• Serial-to-Parallel and Parallel-to-Serial Converters – Efficient data communication

• Counters and Registers – Intermediate data manipulation in sequential circuits

• Educational Electronics Projects – Teach digital data handling and shift register operation

• Embedded Systems – Manage multiple signals with minimal pins

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💡 Advantages:

• Parallel and serial access for versatile data manipulation

• Bidirectional shifting enables flexible control of data flow

• Synchronous operation ensures accurate, high-speed performance

• TTL compatible for easy integration with 7400 series ICs

• Standard DIP package for easy breadboarding and PCB mounting

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📦 Package Includes:

• 1 × 74195 4-Bit Parallel-Access Shift Register IC (DIP-16)

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📘 Conclusion:

The 74195 DIP 4-Bit Parallel-Access Shift Register is a high-performance IC for flexible data storage, transfer, and manipulation. With parallel load, serial shift, bidirectional capability, and synchronous operation, it provides a powerful, reliable solution for digital systems, microcontroller projects, and educational applications, making it a must-have in modern TTL-based electronics.