74HC221D,653

Overview

The 74HC221D,653 is a dual non-retriggerable monostable multivibrator manufactured by NXP USA Inc. It belongs to the HC/UH logic family and utilizes CMOS technology. The device operates within a supply voltage range of 2 V to 6 V and supports an operating temperature range from -40 °C to +125 °C. It is housed in a 16-pin SO package (SOT-338-1). Key electrical characteristics include a maximum propagation delay of 190 ns and output current capabilities of ±5.2 mA. The component features Schmitt-trigger inputs for noise immunity and includes an overriding reset function.

Feature Summary

• Dual non-retriggerable monostable multivibrator configuration
• Schmitt-trigger inputs for improved noise immunity
• Overriding reset capability terminates output pulse
• CMOS technology with low quiescent current

Applications

• Pulse generation circuits
• Timing delays
• Debouncing switches
• Frequency division

Procurement Notes

Verify the specific ordering code suffix to confirm the tape and reel packaging format. Confirm RoHS compliance status as per the latest datasheet revision. Ensure the manufacturer designation matches NXP Semiconductors or Nexperia for authenticity. Check for any recent Product Change Notifications regarding marking or assembly updates before finalizing procurement orders.

Selection Notes

Select this component when a dual non-retriggerable monostable solution is required within the standard 74HC logic family. It serves as a pin-compatible alternative to the 74LS123 series. Consider the 74HCT221 variant if TTL-level input interfacing is necessary instead of CMOS levels. Evaluate the external timing resistor and capacitor requirements against the desired pulse width specifications.

Part Context

This part is part of the widely used 74HC series of high-speed CMOS logic devices. It provides a robust solution for timing applications requiring noise tolerance due to its Schmitt-trigger inputs. The device is designed to be compatible with low-power Schottky TTL standards, facilitating integration into mixed-technology systems.

Replacement Considerations

The 74HCT221D is a direct functional substitute with TTL-compatible input thresholds. Other monostable multivibrators like the 74HC123 are retriggerable and may require circuit adjustments. Verify pinout compatibility and voltage level requirements before substituting.