M74HC238B1R

Overview

The M74HC238B1R is a high-speed CMOS 3-to-8 line decoder manufactured using silicon gate C2MOS technology. It features three binary select inputs (A, B, and C) that determine which of the eight outputs goes high when enabled. The device includes three enable inputs to facilitate cascade connections in memory systems. It operates within a wide voltage range of 2V to 6V, with a typical propagation delay of 15ns at 6V and a maximum quiescent supply current of 4μA.

Feature Summary

• Provides decoding functionality for 3 binary select inputs to activate one of eight outputs
• Includes three enable inputs to support cascading and application-specific control
• Features symmetrical output impedance and balanced propagation delays

Applications

• Memory address decoding systems
• Cascaded logic circuit designs
• General-purpose digital signal routing

Procurement Notes

Verify the specific package type required for your design, as the base part number corresponds to multiple physical packages including DIP, SOP, and TSSOP. Confirm that the ordering suffix matches the desired form factor before finalizing procurement. Ensure compatibility with existing board layouts and mounting requirements.

Selection Notes

Select this component for applications requiring low power dissipation combined with high-speed operation comparable to LSTTL equivalents. Consider the wide operating voltage range and noise immunity characteristics when designing for varying environmental conditions or power supply fluctuations.

Part Context

This component belongs to the STMicroelectronics 74HC series of high-speed CMOS logic devices. It is functionally compatible with the standard 74LS238 series while offering improved power efficiency and performance metrics characteristic of modern CMOS technology implementations.

Replacement Considerations

Direct substitutes include other manufacturers' 74HC238 variants. Verify pinout compatibility and electrical specifications such as propagation delay and output drive capability when considering alternative sources.