74HC4538D,653

Overview

The Nexperia 74HC4538D,653 is a dual retriggerable-resettable precision monostable multivibrator housed in a 16-lead SO plastic small outline package (SOT109-1). It operates on a single supply voltage ranging from 2.0 V to 6.0 V and supports an ambient temperature range of -40 °C to +125 °C. Each multivibrator includes two trigger/retrigger inputs (nA and nB), a direct reset input (nCD), complementary outputs (nQ and nQ), and pins for external timing components (CEXT and REXT). The output pulse width is determined by the formula TW = 0.7 × REXT × CEXT.

Feature Summary

• Dual independent precision monostable multivibrators with separate reset inputs
• Triggering capability from both positive-going and negative-going signal edges
• Schmitt-trigger action on trigger inputs provides tolerance to slow rise and fall times
• Inputs include clamp diodes allowing interface to voltages exceeding VCC via current limiting resistors

Applications

• Pulse generation circuits requiring precise timing control
• Debouncing mechanical switches or contacts
• Frequency division and pulse stretching applications

Procurement Notes

Verify that the ordering suffix '653' corresponds to the specified tape-and-reel packaging format required for automated assembly processes. Confirm the specific package variant matches the SOT109-1 designation to ensure correct footprint compatibility during PCB layout and component placement.

Selection Notes

Select this device when dual independent timing channels are required within a single integrated circuit. Ensure the application utilizes external resistor and capacitor networks to define the desired pulse widths, as internal timing elements are not provided. Verify that the operating voltage remains within the 2.0 V to 6.0 V range for proper functionality.

Part Context

This component belongs to the 74HC series of high-speed CMOS logic devices manufactured by Nexperia. It functions as a specialized timing element distinct from standard logic gates, providing monostable multivibrator capabilities. The device is designed for general-purpose digital and analog switching applications requiring reliable pulse generation.

Replacement Considerations

The 74HC4538PW serves as a functional alternative utilizing a TSSOP16 package instead of the SO16 configuration.