ON Semiconductor MM74HC221AM Dual Monostable Multivibrator

The MM74HC221AM from ON Semiconductor is a high-speed, dual monostable multivibrator designed to operate as a precision timing circuit capable of producing accurate time delays or oscillation. In the monostable mode of operation, the device is triggered by a falling edge on the input signal. Upon triggering, the outputs go to a high state for a controlled period of time based on the external timing components (resistor and capacitor) connected to each multivibrator.

Constructed with advanced silicon-gate CMOS technology, the MM74HC221AM ensures low power consumption and a robust high noise immunity characteristic of CMOS integrated circuits. This makes it an ideal choice for a wide range of applications including timers, pulse generation, sequential logic, and more in consumer electronics, computing devices, and industrial systems.

The device features two individual monostable multivibrators with their own separate inputs and outputs, which provides flexibility in application design. Each multivibrator has an active-low trigger (A) and active-high trigger (B) inputs, clear (CLR) input, and an output (Q). The clear function is asynchronous, and it overrides all other inputs to immediately set the output to a low state when activated.

Key specifications of the MM74HC221AM include:

• Supply Voltage Range: 2V to 6V
• High Noise Immunity: VNIH = VNIL = 28% VCC (Minimum)
• Power Down Protection Provided on Inputs
• Low Power Consumption: 20µA (Maximum) Static Condition
• Standardized Symmetrical Output Characteristics
• Maximum Output Current: 25mA

The MM74HC221AM is provided in a surface-mount SOIC package, making it suitable for compact PCB layouts and automated assembly processes. Its performance is guaranteed over a temperature range of -40°C to +85°C, ensuring reliable operation in challenging environments.

Whether you are designing a timing circuit for a microprocessor system reset or a delay element in a digital signal path, the MM74HC221AM from ON Semiconductor offers a reliable and precise solution that engineers can trust for their critical timing applications.