SN74221N

Overview

The SN74221N is a dual monostable multivibrator from the Texas Instruments 7400 series, housed in a 16-pin PDIP package. It operates within a supply voltage range of 4.75 V to 5.25 V and supports a maximum propagation delay of 80 ns. The device features two independent circuits per chip with a maximum power supply current of 26 mA. It provides a low-level output current of 16 mA and a high-level output current of -800 uA. The component functions reliably across an operating temperature range of 0°C to +70°C.

Feature Summary

• Contains two independent monostable multivibrator circuits for pulse generation and timing control.
• Utilizes Schmitt-trigger inputs to ensure noise immunity and stable triggering.
• Supports direct coupling to TTL logic outputs without requiring external components.

Applications

• Pulse width modulation circuits
• Timing delay generation
• Debouncing switches

Procurement Notes

Verify the specific datasheet revision and RoHS compliance status before procurement, as manufacturing specifications may vary by production batch. Confirm that the 16-PDIP through-hole package aligns with your PCB footprint requirements. Ensure the supply voltage remains strictly within the 4.75 V to 5.25 V range to maintain signal integrity and prevent device damage during operation.

Selection Notes

Select this component when a non-retriggerable monostable configuration is required for precise timing applications. It serves as a suitable alternative to retriggerable variants like the SN74LS123 if single-shot pulse generation is preferred. Consider the 80 ns propagation delay and 26 mA maximum current consumption when designing power-sensitive or high-speed digital systems.

Part Context

This part belongs to the standard 7400 series of logic integrated circuits, widely used in digital electronics for basic logic operations and timing functions. The SN74221N specifically addresses the need for reliable pulse shaping and timing delays in commercial and industrial environments using standard TTL-compatible logic levels.

Replacement Considerations

SN74LS221N

FAQ

Is the SN74221N retriggerable?

No, the SN74221N is a non-retriggerable monostable multivibrator. Once triggered, it completes its full timing cycle regardless of additional trigger pulses.

What type of input triggers does the SN74221N support?

It supports Schmitt-trigger inputs, which provide improved noise immunity compared to standard logic inputs.