CD74HC85E

Overview

The CD74HC85E is a high-speed CMOS logic device functioning as a 4-bit magnitude comparator. It operates within a supply voltage range of 2V to 6V and features non-inverting, active-high outputs. The component supports cascading for expanded bit comparison capabilities. It utilizes a 16-pin PDIP package with through-hole mounting. Electrical characteristics include a maximum propagation delay of 33ns at specified load conditions and output currents of ±5.2mA. The device is rated for an operating temperature range from -55°C to 125°C.

Feature Summary

• Performs 4-bit magnitude comparison between two binary inputs
• Supports cascading via dedicated input pins for multi-bit expansion
• Provides three distinct status outputs indicating greater than, less than, or equal relationships

Applications

• Digital arithmetic logic units requiring magnitude evaluation
• Address decoding systems in microprocessor interfaces
• Control logic circuits comparing numerical values

Procurement Notes

Verify the specific suffix 'E' confirms the PDIP-16 package configuration. Ensure compatibility with HC logic family voltage levels (2V–6V). Confirm lead-free and RoHS compliance status if required by assembly specifications. Cross-reference pinout diagrams against target PCB layout to ensure correct orientation and connection of cascade inputs.

Selection Notes

Select this component when a 4-bit comparison function is required within standard HC logic voltage ranges. Consider the PDIP package only if through-hole manufacturing processes are mandated. Evaluate propagation delay requirements against the 33ns specification under expected load conditions. Verify that the operating temperature range meets environmental constraints of the final application.

Part Context

This part belongs to Texas Instruments' 74HC series of high-speed CMOS logic devices. The 74HC family offers performance comparable to standard TTL but with lower power consumption and wider voltage tolerance. The CD prefix indicates commercial grade temperature rating, while the HC designation specifies the technology node. This comparator integrates multiple gates into a single functional unit for efficient board space utilization.

Replacement Considerations

CD74HC85M96E4 serves as a pin-compatible alternative in SOIC packaging.