74HC191D/AUJ

Product Overview

• Category: Integrated Circuit (IC)
• Use: Counter/Divider
• Characteristics: High-speed, synchronous, up/down counter with parallel load
• Package: SOIC (Small Outline Integrated Circuit)
• Essence: The 74HC191D/AUJ is a versatile counter/divider IC that can count up or down based on the input signals. It also has a parallel load feature, allowing users to preset the initial count value.
• Packaging/Quantity: The 74HC191D/AUJ is typically sold in reels of 2500 units.

Specifications

• Supply Voltage: 2V to 6V
• Operating Temperature Range: -40°C to +125°C
• Maximum Clock Frequency: 25 MHz
• Number of Counting Bits: 4
• Counting Modes: Up, Down, Up/Down Synchronous
• Parallel Load Input: Yes
• Output Type: Standard

Detailed Pin Configuration

The 74HC191D/AUJ has a total of 16 pins. Here is the detailed pin configuration:

1. MR (Master Reset)
2. CP (Clock Pulse)
3. UP/DOWN (Up/Down Control)
4. LD (Parallel Load)
5. A (Data Input A)
6. B (Data Input B)
7. C (Data Input C)
8. D (Data Input D)
9. QA (Output Q0)
10. QB (Output Q1)
11. QC (Output Q2)
12. QD (Output Q3)
13. GND (Ground)
14. VCC (Positive Power Supply)
15. RC (Ripple Carry Output)
16. TC (Terminal Count Output)

Functional Features

• High-speed operation: The 74HC191D/AUJ can operate at clock frequencies up to 25 MHz, making it suitable for applications requiring fast counting.
• Synchronous counting: The counter updates its output values synchronously with the clock signal, ensuring accurate and reliable counting.
• Up/Down control: The UP/DOWN pin allows users to select the counting direction (up or down) based on their application requirements.
• Parallel load capability: The LD pin enables users to preset the initial count value by loading data through the A, B, C, and D inputs.
• Ripple carry output: The RC pin provides a carry-out signal that can be cascaded to other counters for higher bit-counting applications.

Advantages and Disadvantages

Advantages: - High-speed operation allows for efficient counting in time-critical applications. - Synchronous counting ensures accurate and reliable results. - Up/Down control provides flexibility in counting direction. - Parallel load capability allows for easy initialization of the counter. - Ripple carry output enables cascading multiple counters for higher bit-counting.

Disadvantages: - Limited number of counting bits (4 bits) may not be sufficient for certain applications requiring larger counts. - Requires an external clock signal for operation.

Working Principles

The 74HC191D/AUJ is a synchronous counter that operates based on the clock signal provided at the CP pin. When the clock pulse occurs, the counter increments or decrements its count value based on the state of the UP/DOWN pin. The parallel load feature allows users to preset the initial count value by providing data through the A, B, C, and D inputs when the LD pin is activated. The counter's outputs (QA, QB, QC, QD) represent the current count value, while the RC pin provides a carry-out signal for cascading multiple counters.

Detailed Application Field Plans

The 74HC191D/AUJ is commonly used in various applications, including:

1. Digital frequency counters
2. Industrial automation systems
3. Electronic test equipment
4. Automotive electronics
5. Communication systems
6. Robotics

Detailed and Complete Alternative Models

• 74LS191: Low-power Schottky version of the 74HC191D/AUJ with similar functionality.
• CD40192: CMOS version of the counter/divider IC with additional features like asynchronous parallel load.

These alternative models offer similar functionalities to the 74HC191D/AUJ and can be used as replacements depending on specific application requirements.

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