74VHC221AM

Overview

The onsemi 74VHC221AM is a dual non-retriggerable monostable multivibrator fabricated with advanced silicon gate CMOS technology. It operates within a supply voltage range of 2.0 V to 5.5 V and supports an operating temperature range of -40°C to +85°C. The device features two independent circuits, each providing both negative (A) and positive (B) transition triggered inputs, along with a clear input for resetting the output. Propagation delay is typically 8.1 ns at 5 V. Output pulse width is determined by external resistor and capacitor values using the equation PW = Rx * Cx.

Feature Summary

• High-speed operation comparable to Bipolar Schottky TTL while maintaining low power dissipation.
• Includes active state protection on all inputs to prevent device destruction from mismatched supply voltages.
• Pin and function compatible with the 74HC221A series.

Applications

• Timing generation in digital systems
• Pulse width modulation
• Frequency division

Procurement Notes

Verify that the specific ordering code matches the required package type, as surface mount options are available on tape and reel when appending the suffix letter X. Confirm RoHS compliance status through official documentation before procurement. Ensure unused inputs are held HIGH or LOW during operation to maintain functionality.

Selection Notes

Select this component for applications requiring high-speed monostable triggering with low quiescent current. The device supports interfacing between 5 V and 3 V systems due to its input protection circuit. Consider the external timing components' leakage characteristics when selecting Rx and Cx values to ensure accurate pulse width generation.

Part Context

This part belongs to the 74VHC logic family, designed for high-speed CMOS applications. It serves as a direct pin-compatible alternative to the 74HC221A, offering improved speed performance. The device is manufactured using silicon gate CMOS technology to achieve fast switching times while minimizing power consumption.

Replacement Considerations

Direct substitutes include the SN74LV221ANSR from Texas Instruments. Verify compatibility regarding supply voltage ranges and package dimensions before replacement.