M74HC298B1R

Overview

The M74HC298B1R is a high-speed CMOS Quad 2-Channel Multiplexer/Register fabricated with silicon gate C2MOS technology. It operates within a supply voltage range of 2V to 6V and features an operating temperature range from -55°C to +125°C. The device includes Word Select and Clock inputs, where the select word is clocked to output terminals on the negative edge of the clock pulse. Key electrical specifications include a maximum clock frequency of 79 MHz at 6V, a quiescent supply current of 4µA maximum at 25°C, and symmetrical output impedance with |IOH| = IOL = 4mA minimum.

Feature Summary

• Quad 2-channel multiplexer/register functionality controlled by Word Select and Clock signals
• High noise immunity with input thresholds defined as 28% of VCC
• Balanced propagation delays between low-to-high and high-to-low transitions
• Integrated protection circuits against static discharge and transient excess voltage

Applications

• Data routing in digital systems requiring dual-word selection
• Parallel data storage applications utilizing flip-flop outputs
• Multiplexing operations in high-speed CMOS logic circuits

Procurement Notes

Verify component authenticity through authorized STMicroelectronics distributors or certified partners. Confirm package type matches requirements, as this part number corresponds to the DIP variant. Check for RoHS compliance status and ensure handling procedures account for ESD sensitivity despite built-in protection circuits. Validate that the obsolete status does not impact long-term project viability.

Selection Notes

Select this component when dual-channel multiplexing with integrated register capability is required. Ensure the application voltage falls within the 2V to 6V range. Consider the negative edge-triggered clock operation for timing alignment. Verify that the DIP package dimensions fit the target PCB layout constraints compared to SOP or TSSOP alternatives.

Part Context

This component belongs to the M74HC298 series of quad 2-channel multiplexer/registers. It is part of STMicroelectronics' HC logic family, designed for high-speed CMOS applications. The series offers pin and function compatibility with standard 74 series equivalents, facilitating direct replacement in legacy designs while providing improved speed and power characteristics typical of modern CMOS technology.

Replacement Considerations

Direct substitutes include M74HC298M1R (SOP) and M74HC298TTR (TSSOP). Cross-manufacturer compatible parts should be verified for identical pinout and electrical specifications.