M74HC251B1R

Overview

The M74HC251B1R is an 8-channel multiplexer with 3-state outputs fabricated using silicon gate C2MOS technology. It features true (Y) and complement (W) outputs controlled by a STROBE input. The device operates within a supply voltage range of 2V to 6V, providing high noise immunity where VNIH and VNIL are at least 28% of VCC. Propagation delay from data inputs to outputs is typically 17ns at 6V. It includes protection circuits against static discharge and transient excess voltage on all inputs.

Feature Summary

• Provides both true and complementary outputs for flexible signal routing
• Features a STROBE input to enable or disable outputs into a high impedance state
• Includes built-in protection circuits against static discharge and transient excess voltage

Applications

• Data acquisition systems requiring multi-channel selection
• Digital logic signal routing and switching applications
• Microprocessor-based systems utilizing address decoding for data selection

Procurement Notes

Verify the specific package type required for your design, as the B1R suffix corresponds to the DIP-16 package. Confirm that the operating temperature range of -55°C to +125°C meets your environmental specifications. Ensure that the power dissipation limits and thermal derating requirements are accounted for in your PCB layout to maintain reliable operation under maximum load conditions.

Selection Notes

Select this component when an 8-channel multiplexing function with tri-state outputs is required. It is suitable for designs needing simultaneous access to true and inverted signals. Consider the wide operating voltage range if interfacing with various logic families. Verify that the propagation delays meet the timing constraints of your system clock speeds.

Part Context

This part belongs to the M74HC series of high-speed CMOS logic devices manufactured by STMicroelectronics. The HC series is known for low power consumption and compatibility with standard TTL logic levels. The M74HC251 specifically implements an 8-input multiplexer architecture, distinguishing it from other logic functions like decoders or shift registers within the same product family.

Replacement Considerations

Check for pin-compatible alternatives such as the M74HC251M1R (SOP package) or M74HC251TTR (TSSOP package) if different form factors are needed. Other manufacturers may offer equivalent 74HC251 parts, but verify electrical characteristics and package dimensions carefully.