DM74LS221N

Product Overview

• Category: Integrated Circuit
• Use: Dual Monostable Multivibrator
• Characteristics: TTL Logic, Schottky-clamped TTL, 16-pin DIP package
• Package: 16-pin DIP (Dual In-line Package)
• Essence: The DM74LS221N is a dual monostable multivibrator integrated circuit that is widely used in digital electronics applications.
• Packaging/Quantity: Available in tubes or reels with varying quantities.

Specifications

• Supply Voltage: 4.75V to 5.25V
• Operating Temperature: 0°C to 70°C
• Propagation Delay: 15 ns
• Trigger Pulse Width: 30 ns to 50 ns
• Output Pulse Width: 100 ns to 200 ns
• Input Current: 1.6 mA
• Output Current: -0.4 mA to 8 mA

Detailed Pin Configuration

The DM74LS221N has a total of 16 pins. Here is the detailed pin configuration:

1. CLR (Clear) - Active LOW input for resetting the multivibrator.
2. A (Trigger) - Active HIGH input for triggering the multivibrator.
3. B (Trigger) - Active HIGH input for triggering the multivibrator.
4. Rext (External Resistor) - Connects an external resistor to control the pulse width.
5. Cext (External Capacitor) - Connects an external capacitor to control the pulse width.
6. VCC (Positive Power Supply) - Connects to the positive power supply.
7. Q1 (Output) - Output of the first monostable multivibrator.
8. Q2 (Output) - Output of the second monostable multivibrator.
9. GND (Ground) - Connects to the ground.
10. Q2 (Output) - Output of the second monostable multivibrator.
11. Q1 (Output) - Output of the first monostable multivibrator.
12. VCC (Positive Power Supply) - Connects to the positive power supply.
13. Cext (External Capacitor) - Connects an external capacitor to control the pulse width.
14. Rext (External Resistor) - Connects an external resistor to control the pulse width.
15. B (Trigger) - Active HIGH input for triggering the multivibrator.
16. A (Trigger) - Active HIGH input for triggering the multivibrator.

Functional Features

• Dual monostable multivibrator with independent trigger inputs.
• Can be used to generate accurate time delays or pulses.
• TTL logic and Schottky-clamped TTL inputs ensure high-speed operation.
• Stable output pulse width regardless of trigger pulse duration.
• Wide operating voltage range.

Advantages and Disadvantages

Advantages: - Accurate and stable output pulse width. - High-speed operation. - Easy to use and integrate into digital circuits. - Wide operating voltage range.

Disadvantages: - Limited number of trigger inputs. - Requires external resistors and capacitors for pulse width control.

Working Principles

The DM74LS221N is a dual monostable multivibrator that generates a single output pulse of a fixed duration when triggered by an input signal. It consists of two independent monostable circuits, each triggered by separate inputs (A and B). The output pulse width is determined by external resistors and capacitors connected to the Rext and Cext pins.

When a trigger input goes HIGH, the corresponding monostable circuit is triggered, generating an output pulse. The pulse width is determined by the values of the external resistor and capacitor. The output pulse width remains constant regardless of the duration of the trigger input.

Detailed Application Field Plans

The DM74LS221N can be used in various applications, including:

1. Timing circuits: It can be used to generate accurate time delays in digital systems.
2. Pulse generation: It can generate precise pulses for controlling other digital circuits.
3. Sequential logic circuits: It can be used as a building block in sequential logic circuits.
4. Communication systems: It can be used in timing and synchronization circuits in communication systems.
5. Industrial automation: It can be used in control systems for precise timing operations.

Detailed and Complete Alternative Models

• SN74LS221N
• CD74LS221N
• MC74LS221N
• 74HC221N
• 74HCT221N

These alternative models offer similar functionality and can be used as replacements for the DM74LS221N in various applications.

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