M74HC221B1R

Multivibrators Overview

The M74HC221B1R is a dual monostable multivibrator fabricated with silicon gate C2MOS technology. It operates within a supply voltage range of 2V to 6V and features two trigger inputs per circuit: Input A for negative edge triggering and Input B for positive edge triggering. The device provides both active high (Q) and active low (/Q) outputs. Timing is determined by external resistor Rx and capacitor Cx, supporting output pulse widths from 150 ns to 60 s at VCC = 4.5V. It includes direct reset functionality via the CLR input.

Multivibrators Feature Summary

• Dual independent monostable circuits with symmetrical output impedance
• Flexible triggering options using negative edge on Input A or positive edge on Input B
• Direct reset capability through the CLR input to terminate the monostable state
• High noise immunity with Schmitt-trigger characteristics on specific inputs

Multivibrators Applications

• Pulse generation and timing control in digital systems
• Debouncing mechanical switches
• Delay line applications requiring precise time intervals
• Retriggerable timing sequences in industrial control logic

Multivibrators Procurement Notes

Verify that the component matches the DIP-16 package configuration specified for the M74HC221B1R ordering code. Confirm the manufacturer is STMicroelectronics and check datasheet revisions for any updates to absolute maximum ratings or operating temperature ranges before integration into final designs.

Multivibrators Selection Notes

Select this component when dual independent monostable functions are required in a single package. Ensure external Rx and Cx values comply with recommended limits, specifically keeping Rx between 1kΩ and 1MΩ for VCC ≥ 3V. Consider the wide operating voltage range and CMOS power dissipation characteristics for low-power system designs.

Multivibrators Part Context

This part belongs to the M74HC series of high-speed CMOS logic devices. It is functionally compatible with the standard 74 Series 221 but utilizes advanced silicon gate C2MOS technology for improved speed and lower power consumption. The B1R suffix indicates the specific tube packaging format for the DIP-16 variant.

Multivibrators Replacement Considerations

Compatible substitutes include other dual monostable multivibrators such as the HCC4098B or generic 74HC221 equivalents from other manufacturers, provided pinouts and electrical specifications align with the design requirements.