CD74HC221M

Product Overview

• Category: Integrated Circuit
• Use: Digital Logic Gate
• Characteristics: High-Speed, Dual Monostable Multivibrator
• Package: SOIC (Small Outline Integrated Circuit)
• Essence: Monostable Multivibrator IC
• Packaging/Quantity: Tape and Reel, 2500 pieces per reel

Specifications

• Supply Voltage Range: 2V to 6V
• High-Level Input Voltage: 2V to VCC
• Low-Level Input Voltage: GND to 0.8V
• High-Level Output Current: -4mA
• Low-Level Output Current: 4mA
• Propagation Delay Time: 15ns
• Trigger Pulse Width: 20ns
• Reset Pulse Width: 20ns

Detailed Pin Configuration

The CD74HC221M has a total of 16 pins, which are assigned as follows:

1. CLR (Clear) - Active LOW input for resetting the multivibrator.
2. A (Input A) - First input for setting the desired pulse width.
3. B (Input B) - Second input for setting the desired pulse width.
4. RC (Resistor-Capacitor) - External resistor-capacitor timing components connection pin.
5. Q (Output Q) - Output of the first monostable multivibrator.
6. Q̅ (Output Q̅) - Complementary output of the first monostable multivibrator.
7. GND (Ground) - Ground reference voltage.

8. VCC (Voltage Common Collector) - Positive power supply voltage.

9. Q (Output Q) - Output of the second monostable multivibrator.

10. Q̅ (Output Q̅) - Complementary output of the second monostable multivibrator.
11. B (Input B) - Second input for setting the desired pulse width.
12. A (Input A) - First input for setting the desired pulse width.
13. CLR (Clear) - Active LOW input for resetting the multivibrator.
14. RC (Resistor-Capacitor) - External resistor-capacitor timing components connection pin.
15. GND (Ground) - Ground reference voltage.
16. VCC (Voltage Common Collector) - Positive power supply voltage.

Functional Features

• Dual monostable multivibrator with independent inputs and outputs.
• Provides precise control over pulse width generation.
• High-speed operation suitable for time-critical applications.
• Wide supply voltage range allows flexibility in various systems.
• Complementary outputs facilitate easy interfacing with other logic circuits.

Advantages and Disadvantages

Advantages: - Precise control over pulse width generation. - High-speed operation. - Wide supply voltage range. - Easy interfacing with other logic circuits.

Disadvantages: - Limited number of timing components can be connected externally. - Not suitable for applications requiring extremely long pulse widths.

Working Principles

The CD74HC221M is a dual monostable multivibrator IC that generates a pulse of a specific width based on the input signals provided. It consists of two independent monostable multivibrators, each with its own set of inputs and outputs. The pulse width is determined by the values of external resistors and capacitors connected to the RC pins.

When a trigger pulse is applied to the A or B input, the corresponding monostable multivibrator generates an output pulse whose width is determined by the RC timing components. The output remains high for the duration of the pulse width and then returns to low state. The CLR input can be used to reset the multivibrator and terminate the output pulse prematurely.

Detailed Application Field Plans

The CD74HC221M is commonly used in various applications that require precise control over pulse width generation. Some of the specific application fields include:

1. Timing circuits: The IC is widely used in timing circuits where accurate and adjustable pulse widths are required, such as in clock synchronization systems, frequency dividers, and delay generators.

2. Communication systems: It finds applications in communication systems for generating precise timing signals, synchronization pulses, and data encoding/decoding.

3. Industrial automation: The IC is utilized in industrial automation systems for controlling timing sequences, motor control, and sensor interfacing.

4. Test and measurement equipment: It is employed in test and measurement instruments for generating precise trigger signals, time intervals, and waveform shaping.

Detailed and Complete Alternative Models

• CD74HC123M
• CD74HCT221M
• SN74HC221N
• MC74HC221AN
• 74HC221D

These alternative models offer similar functionality and can be used as substitutes for the CD74HC221M in various applications.

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