Encyclopedia Entry: 74AC191SCX

Product Overview

Category

The 74AC191SCX belongs to the category of integrated circuits (ICs).

Use

This IC is commonly used in digital electronic systems for various applications, including counters and registers.

Characteristics

• The 74AC191SCX is a synchronous up/down binary counter.
• It operates on a wide voltage range, typically between 2V and 6V.
• This IC offers high-speed operation and low power consumption.
• It is designed to be compatible with both TTL and CMOS logic families.

Package

The 74AC191SCX is available in a small outline package (SOIC) format.

Essence

The essence of this IC lies in its ability to perform counting operations in digital circuits accurately and efficiently.

Packaging/Quantity

The 74AC191SCX is typically packaged in reels or tubes, containing a quantity of 250 units per package.

Specifications

• Supply Voltage Range: 2V to 6V
• Operating Temperature Range: -40°C to +85°C
• Maximum Clock Frequency: 100 MHz
• Number of Counting Bits: 4
• Logic Family Compatibility: TTL and CMOS

Detailed Pin Configuration

The 74AC191SCX has a total of 16 pins, each serving a specific purpose. Here is the detailed pin configuration:

1. CP (Clock Pulse): Input pin for clock signal.
2. MR (Master Reset): Active-low input pin for resetting the counter.
3. U/D (Up/Down): Input pin for selecting count direction (up or down).
4. D0-D3 (Data Inputs): Four input pins for setting the initial count value.
5. QA-QD (Outputs): Four output pins representing the current count value.
6. RC (Ripple Carry): Output pin for cascading multiple counters.
7. CET (Count Enable Parallel Load): Input pin for parallel loading of count value.
8. PE (Preset Enable): Input pin for enabling presetting of the counter.

Functional Features

• Synchronous Counting: The 74AC191SCX performs counting operations synchronously with the clock signal, ensuring accurate and reliable results.
• Up/Down Counting: It supports both up and down counting modes, depending on the input provided to the U/D pin.
• Parallel Loading: The counter can be loaded with a specific count value in parallel using the CET pin.
• Cascading Capability: The RC output allows for cascading multiple counters to achieve higher counting ranges.
• Preset Functionality: The counter can be preset to a specific count value using the PE pin.

Advantages and Disadvantages

Advantages

• High-speed operation enables efficient counting in time-critical applications.
• Wide voltage range compatibility makes it suitable for various digital systems.
• Low power consumption helps in reducing overall system energy requirements.
• Compatibility with TTL and CMOS logic families ensures easy integration into existing circuits.

Disadvantages

• Limited counting range due to the 4-bit configuration.
• Lack of built-in error detection or correction mechanisms.

Working Principles

The 74AC191SCX operates based on synchronous counting principles. When a clock pulse is received at the CP pin, the counter increments or decrements its current count value based on the state of the U/D pin. The count value can also be preset using the CET and PE pins. The outputs QA-QD represent the current count value, while the RC pin allows for cascading multiple counters.

Detailed Application Field Plans

The 74AC191SCX finds applications in various fields where accurate counting is required. Some detailed application field plans include: 1. Digital frequency dividers 2. Industrial automation systems 3. Digital communication equipment 4. Automotive electronics 5. Test and measurement instruments

Detailed and Complete Alternative Models

• 74HC191: A similar 4-bit synchronous up/down binary counter with TTL logic compatibility.
• CD40193: A 4-bit synchronous up/down binary counter with CMOS logic compatibility.
• SN74LS191: A 4-bit synchronous up/down binary counter with TTL logic compatibility.

These alternative models offer similar functionality to the 74AC191SCX and can be used as replacements in various applications.

In conclusion, the 74AC191SCX is a versatile integrated circuit that serves as a synchronous up/down binary counter. Its high-speed operation, low power consumption, and compatibility with different logic families make it suitable for a wide range of digital electronic systems.