The TC74HC4538AFT is a high-speed CMOS dual retriggerable monostable multivibrator manufactured by Toshiba Semiconductor and Storage. This integrated circuit provides two independent monostable multivibrators (one-shots) within a single package. Each multivibrator can be triggered by either a positive-going or negative-going edge, and the output pulse width is determined by an external resistor and capacitor. The retriggerable function allows the output pulse to be extended if a new trigger occurs before the timeout period has elapsed.

Applications

• Timers and pulse generators
• Delay circuits
• Missing pulse detectors
• Contact debounce circuits
• Sequential timing circuits

Features

• High-speed operation
• Low power consumption
• Wide operating voltage range: 2V to 6V
• Dual monostable multivibrators
• Retriggerable operation
• Positive- or negative-edge triggering
• Output pulse width controlled by external RC components
• Operating temperature range: -40°C to +85°C

Benefits

• Versatile timing functions with two independent monostable multivibrators.
• Retriggerable operation allows for extended output pulses.
• Positive- or negative-edge triggering provides flexibility in triggering options.
• Precise output pulse width control with external RC components.
• Low power consumption extends battery life.
• High noise immunity.

Additional Details

The TC74HC4538AFT is available in a SOP-16 (Small Outline Package). The output pulse width is determined by the values of the external resistor (R) and capacitor (C) connected to the timing pins. The pulse width is approximately equal to 0.7 x R x C. The device can be triggered by applying a pulse to the trigger input. The trigger input can be configured to respond to either a positive-going or negative-going edge by applying the appropriate voltage level to the A/B input. The CLEAR input provides a means of terminating the output pulse prematurely.

The supply voltage range is typically between 2V and 6V, with recommended operating conditions specified in the datasheet. The trigger pulse width must be shorter than the output pulse width. The device is designed to be compatible with other HC series logic devices.