Encyclopedia Entry: 74AC161SJ

Product Overview

Category

The 74AC161SJ 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 purposes in various electronic applications. It can be employed in digital systems where sequential counting is required.

Characteristics

• The 74AC161SJ is a synchronous presettable binary counter.
• It operates on a supply voltage range of 2V to 6V.
• This IC offers high-speed operation with low power consumption.
• It has a compact package size, making it suitable for space-constrained designs.

Package and Quantity

The 74AC161SJ is available in a standard 16-pin dual in-line package (DIP). Each package contains one IC.

Specifications

• Maximum Clock Frequency: 125 MHz
• Number of Counting Stages: 4
• Maximum Supply Voltage: 6V
• Minimum Supply Voltage: 2V
• Operating Temperature Range: -40°C to +85°C

Pin Configuration

The pin configuration of the 74AC161SJ is as follows:

┌───┬───┐ Q0 |1 16| Vcc Q1 |2 15| MR Q2 |3 14| CP Q3 |4 13| PE TC |5 12| CET PL |6 11| Q3 GND|7 10| Q2 └───┴───┘

Pin Description

• Q0-Q3: Output pins representing the binary count value.
• Vcc: Positive power supply terminal.
• MR: Master Reset input for clearing the counter.
• CP: Clock Pulse input for advancing the counter.
• PE: Parallel Enable input for presetting the counter.
• TC: Terminal Count output indicating when the counter reaches its maximum value.
• PL: Parallel Load input for loading a specific count value.
• CET: Carry Enable input for enabling cascading multiple counters.
• GND: Ground terminal.

Functional Features

The 74AC161SJ offers the following functional features:

1. Synchronous Operation: The counter advances on each clock pulse, ensuring accurate counting in synchronous systems.
2. Presettable Functionality: The counter can be loaded with a specific count value using the parallel load input (PL).
3. Master Reset Capability: The counter can be reset to its initial state using the master reset input (MR).
4. Terminal Count Output: The terminal count (TC) output signals when the counter reaches its maximum value.
5. Cascadable Design: Multiple counters can be connected in cascade using the carry enable input (CET).

Advantages and Disadvantages

Advantages

• High-speed operation allows for efficient counting in time-critical applications.
• Low power consumption makes it suitable for battery-powered devices.
• Compact package size enables integration into space-constrained designs.
• Synchronous operation ensures accurate counting in synchronized systems.

Disadvantages

• Limited number of counting stages (4 in this case) may not suffice for certain complex applications.
• Requires external components for proper functionality, such as clock source and power supply.

Working Principles

The 74AC161SJ operates based on the principles of synchronous binary counting. It utilizes flip-flops to store and propagate the count values. On each clock pulse, the counter advances by one count, following the binary sequence. The counter can be preset to a specific count value using the parallel load input. The master reset input clears the counter to its initial state. The terminal count output indicates when the counter reaches its maximum value.

Application Field Plans

The 74AC161SJ can be utilized in various applications, including: 1. Digital frequency dividers 2. Event counters 3. Timers and clocks 4. Industrial automation systems 5. Communication equipment

Alternative Models

Some alternative models to the 74AC161SJ include: - 74HC161: Similar synchronous presettable binary counter with a wider supply voltage range. - CD40161B: Presettable up/down counter with additional functionality. - 74LS161: Asynchronous presettable binary counter with different characteristics.

These alternative models provide similar counting capabilities but may differ in terms of power consumption, speed, and package size.

In conclusion, the 74AC161SJ is a versatile synchronous presettable binary counter IC that offers high-speed operation, low power consumption, and compact packaging. Its functional features, advantages, and disadvantages make it suitable for various digital counting applications in different fields.