Encyclopedia Entry: 74AC191SC

Product Overview

Category

The 74AC191SC belongs to the category of integrated circuits (ICs) and specifically falls under the family of digital counters.

Use

This IC is primarily used for counting and storing binary data in electronic circuits. It can be employed in various applications that require sequential counting or frequency division.

Characteristics

• The 74AC191SC is a synchronous up/down counter with a parallel load feature.
• It operates on a wide supply voltage range, typically between 2V and 6V.
• This IC offers high-speed operation and low power consumption.
• It has a compact package size, making it suitable for space-constrained designs.
• The 74AC191SC exhibits excellent noise immunity and robustness against voltage fluctuations.

Package and Quantity

The 74AC191SC is available in a small outline integrated circuit (SOIC) package. It consists of 16 pins arranged in a compact form factor. These packages are commonly sold in reels or tubes containing multiple units.

Specifications

• Supply Voltage Range: 2V - 6V
• Operating Temperature Range: -40°C to +85°C
• Maximum Clock Frequency: 100 MHz
• Maximum Counting Range: 0 to 15 (4-bit binary)
• Input Logic Levels: TTL/CMOS compatible
• Output Logic Levels: CMOS compatible

Pin Configuration

The 74AC191SC features 16 pins, each serving a specific function. The pin configuration is as follows:

1. MR (Master Reset)
2. CPD (Count Down Clock Pulse)
3. CUD (Count Up Clock Pulse)
4. PL (Parallel Load)
5. D0 (Data Input 0)
6. D1 (Data Input 1)
7. D2 (Data Input 2)
8. D3 (Data Input 3)
9. Q0 (Output Bit 0)
10. Q1 (Output Bit 1)
11. Q2 (Output Bit 2)
12. Q3 (Output Bit 3)
13. GND (Ground)
14. VCC (Supply Voltage)
15. CARRY OUT
16. BORROW OUT

Functional Features

The 74AC191SC offers the following functional features:

• Synchronous counting in both up and down directions.
• Parallel loading of data into the counter.
• Master reset functionality to clear the counter.
• Carry and borrow outputs for cascading multiple counters.
• High-speed operation with minimal propagation delay.

Advantages and Disadvantages

Advantages

• Wide supply voltage range allows compatibility with various systems.
• Compact package size enables integration into space-constrained designs.
• Low power consumption ensures energy efficiency.
• Excellent noise immunity ensures reliable operation in noisy environments.
• Versatile functionality supports a wide range of applications.

Disadvantages

• Limited counting range (0 to 15) due to its 4-bit architecture.
• Requires external components for cascading multiple counters.

Working Principles

The 74AC191SC operates based on synchronous counting principles. It utilizes clock pulses to increment or decrement the count value stored internally. The parallel load feature allows the user to load a specific count value directly into the counter. The carry and borrow outputs facilitate cascading multiple counters to achieve larger counting ranges.

Application Field Plans

The 74AC191SC finds applications in various fields, including:

1. Digital frequency dividers
2. Industrial automation systems
3. Electronic test equipment
4. Communication devices
5. Automotive electronics
6. Consumer electronics

Alternative Models

Several alternative models offer similar functionality to the 74AC191SC. Some notable alternatives include:

1. 74HC191: A CMOS version of the counter with a wider supply voltage range.
2. CD40193: A 4-bit synchronous up/down counter with similar characteristics.
3. SN74LS191: A TTL-compatible version with enhanced noise immunity.

These alternative models can be considered based on specific project requirements and compatibility with existing systems.

In conclusion, the 74AC191SC is a versatile integrated circuit that serves as a synchronous up/down counter. Its compact size, low power consumption, and wide supply voltage range make it suitable for various applications in different fields.