MC74HC4538ADTR2

Multivibrators Overview

The MC74HC4538ADTR2 is a dual precision monostable multivibrator manufactured by onsemi. It operates within a supply voltage range of 3.0 V to 6.0 V and features two independent circuits per package. The device accepts positive-edge triggers at input A or negative-edge triggers at input B, with no restrictions on trigger rise and fall times. Output pulse width is determined by external timing components Rx and Cx. Propagation delays from input A or B to Q are 195 ns, 39 ns, and 33 ns maximum at 2.0 V, 4.5 V, and 6.0 V respectively. Maximum quiescent supply current is 130 uA at 6.0 V.

Multivibrators Feature Summary

• Retriggerable operation allows output pulse extension when triggered during the timing cycle.
• Conditioned trigger inputs eliminate restrictions on signal rise and fall times.
• Active-low reset function forces outputs to defined states regardless of pulse circuitry status.
• Outputs directly interface with CMOS, NMOS, and TTL logic families.

Multivibrators Applications

• Pulse generation and shaping in digital systems
• Timing delay circuits for sequential logic control
• Debouncing switches or mechanical contacts

Multivibrators Procurement Notes

Verify component authenticity through authorized distribution channels. Confirm RoHS compliance and lead-free packaging status against the specific order code suffix. Ensure storage conditions adhere to moisture sensitivity level requirements prior to soldering.

Multivibrators Selection Notes

Select this component for applications requiring precise timing intervals adjustable via external resistors and capacitors. Verify that the operating voltage falls between 3.0 V and 6.0 V. Consider the TSSOP-16 package dimensions for PCB layout constraints.

Multivibrators Part Context

This part belongs to the HC4538A series of high-speed CMOS logic devices. It shares pinout compatibility with legacy MC14538B designs while offering improved speed characteristics typical of the HC family. The ADTR2 suffix indicates a tape and reel packaging format suitable for automated surface-mount assembly processes.

Multivibrators Replacement Considerations

MC74HC4538ADR2G

Multivibrators FAQ

How does the retriggerable feature affect the output pulse width?

If a new trigger occurs while the output pulse is active, the timing cycle restarts, extending the total output pulse duration beyond the initial calculated width.

What happens to the timing capacitor during power-down?

Large timing capacitors may discharge through input protection diodes. An external damping diode is recommended to prevent damage if the supply voltage drops rapidly.