MM74HC4538SJX

Overview

The MM74HC4538SJX is a dual retriggerable precision monostable multivibrator implemented in advanced silicon-gate CMOS technology. It features Schmitt trigger inputs for both negative (A) and positive (B) transitions, with either input capable of functioning as an inhibit input. A dedicated clear input resets the device when taken low. The circuit generates output pulses with a width defined by PW = 0.7(R)(C). It operates within a supply voltage range of 2V to 6V, offering propagation delays typically around 32ns at 5V. The device provides a fanout of 10 LS-TTL loads and maintains low input current characteristics.

Feature Summary

• Dual retriggerable precision monostable multivibrator architecture
• Schmitt trigger inputs on both A and B channels
• Retriggerable pulse extension capability during active output
• Dedicated clear input for immediate reset functionality

Applications

• Pulse generation circuits requiring precise timing control
• Debouncing switches or contacts in digital systems
• Timing delay applications in logic interfaces

Procurement Notes

Verify the specific manufacturer source, as MM74HC4538SJX appears primarily associated with onsemi in distributor databases while Fairchild Semiconductor was historically linked to the base MM74HC4538 part number. Confirm RoHS compliance status and package type (SOP-16) against the specific supplier's documentation. Ensure the ordering suffix matches the required tape and reel configuration if applicable.

Selection Notes

Select this component when dual independent monostable timers are required in a single package. It is suitable for designs needing high noise immunity and low power consumption typical of CMOS technology. Consider the wide supply voltage range and temperature stability when designing for varying environmental conditions. Verify that the external RC components can achieve the desired pulse width stability across the operating temperature range.

Part Context

This device belongs to the 74HC series of high-speed CMOS logic devices. It is pin-compatible with CD4528 and CD4538 one-shots, facilitating design upgrades from older technologies. The MM74HC4538 variant specifically denotes the dual monostable multivibrator function within the broader 74HC family of integrated circuits.

Replacement Considerations

CD74HC4538M and 74HC4538N are documented pin-compatible alternatives. Verify electrical specifications and package availability before substitution.