CD74HCT147E

Overview

The CD74HCT147E is a High-Speed CMOS Logic 10-to-4-Line Priority Encoder manufactured by Texas Instruments. It features buffered inputs and outputs, with a typical propagation delay of 13ns at VCC = 5V, CL = 15pF, TA = 25°C. The device operates within a supply voltage range of 2V to 6V for HC types, though HCT variants typically require 4.5V to 5.5V. It is housed in a 16-pin PDIP package.

Feature Summary

• Implements 10-to-4-line priority encoding functionality
• Utilizes High-Speed CMOS technology for significant power reduction compared to LSTTL
• Provides balanced propagation delay and transition times
• Features buffered inputs and outputs

Applications

• Digital systems requiring decimal-to-binary conversion
• Keyboard encoder circuits
• Data acquisition systems
• Microprocessor interface logic

Procurement Notes

Verify the specific datasheet version for the CD74HCT147E, as HCT specifications may differ from HC series regarding voltage ranges. Confirm the 16-pin PDIP package availability matches your PCB footprint requirements. Ensure operating conditions align with the 4.5V to 5.5V typical HCT supply range rather than the broader 2V to 6V HC range found in some generic descriptions.

Selection Notes

Select this component when active high or low encoded binary output is required from ten input lines. The HCT series ensures TTL-compatible input levels while offering CMOS output drive capabilities. Consider the 16-pin DIP package for through-hole prototyping or legacy board designs where surface mount options are not feasible.

Part Context

This part belongs to the Texas Instruments 74HCT family of high-speed CMOS logic devices. The 74HCT series is designed to be pin-compatible and functionally equivalent to 74LS TTL logic but with lower power consumption and higher noise immunity. The CD74 prefix indicates commercial temperature range and standard packaging.

Replacement Considerations

CD74HC147E: HC series variant with wider voltage range (2V-6V) but different input threshold characteristics. SN74HCT147N: Alternative manufacturer or package option. Verify logic polarity and pinout compatibility before substitution.