CD74ACT646M Equivalent & Substitute Parts

Part Overview

The CD74ACT646M is a non-inverting transceiver logic IC manufactured by Texas Instruments, designed for 8-bit bidirectional data transfer with 3-state output capability. This device operates across a 4.5V to 5.5V supply range and is housed in a 24-SOIC surface mount package. The CD74ACT646M is classified as Last Time Buy, indicating end-of-life status. Identifying equivalent and substitute parts is necessary to ensure design continuity, maintain supply chain flexibility, and support long-term product availability for applications requiring this transceiver functionality.

Substiute Parts

CD74ACT646M

Texas InstrumentsIn Stock: 1320CD74ACT646M Datasheet

Current PartRFQ

CD74ACT646M96

Texas InstrumentsIn Stock: 1001CD74ACT646M96 Datasheet

MFR RecommendedRFQ

MC74ACT646DWG

onsemiIn Stock: 972MC74ACT646DWG Datasheet

MFR RecommendedRFQ

MC74ACT646DWR2G

onsemiIn Stock: 972MC74ACT646DWR2G Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the CD74ACT646M is determined by the following critical parameters: logic type (non-inverting transceiver), element and bit configuration (1 element, 8 bits per element), output type (3-state), output current capability (24mA minimum for both high and low), supply voltage range (4.5V to 5.5V), package type (24-SOIC), and mounting method (surface mount). All substitute parts must maintain identical or superior electrical characteristics within these core specifications. Packaging format differences (tube versus tape & reel) do not affect functional equivalence but may impact procurement and handling requirements.

Parameter Comparison

Engineering Selection Recommendations

CD74ACT646M96 is the primary recommended substitute. This Texas Instruments part maintains identical electrical specifications and packaging while offering Active product status, ensuring continued availability and support. The tape & reel packaging format accommodates high-volume manufacturing environments, whereas the original tube packaging suits lower-volume applications.

MC74ACT646DWG and MC74ACT646DWR2G are onsemi equivalents with full functional compatibility. Both parts are classified as Obsolete, limiting their suitability for new designs or long-term supply assurance. Additionally, these onsemi variants operate within a narrower temperature range (-40°C to 85°C versus -55°C to 125°C) and carry a higher moisture sensitivity level (MSL 3 versus MSL 1), requiring stricter handling and storage protocols during manufacturing and assembly.

For applications requiring extended temperature operation or unlimited moisture tolerance, CD74ACT646M96 is the optimal choice. For cost-sensitive applications where temperature and moisture constraints are acceptable, onsemi alternatives may be considered with appropriate supply chain validation.

Frequently Asked Questions (FAQ)

Q: Can CD74ACT646M96 be used as a direct replacement for CD74ACT646M?

A: Yes. CD74ACT646M96 is functionally equivalent, maintaining identical logic type, bit configuration, output current, supply voltage, and package specifications. The primary difference is packaging format (tape & reel versus tube) and product status (Active versus Last Time Buy).

Q: What is the significance of the operating temperature difference between CD74ACT646M and the onsemi alternatives?

A: The CD74ACT646M and CD74ACT646M96 operate from -55°C to 125°C, while MC74ACT646DWG and MC74ACT646DWR2G operate from -40°C to 85°C. Applications requiring full military or extended temperature range operation must use Texas Instruments parts. Onsemi alternatives are suitable only for commercial temperature applications.

Q: How does Moisture Sensitivity Level (MSL) affect part selection?

A: CD74ACT646M and CD74ACT646M96 carry MSL 1 (Unlimited), allowing indefinite storage without moisture baking. MC74ACT646DWG and MC74ACT646DWR2G carry MSL 3 (168 Hours), requiring moisture baking before assembly if storage exceeds 168 hours. This impacts manufacturing logistics and cost.

Q: Are there packaging considerations when switching from CD74ACT646M to CD74ACT646M96?

A: CD74ACT646M is supplied in tube packaging, while CD74ACT646M96 is supplied in tape & reel format. Both are 24-SOIC surface mount packages with identical pinout and footprint. Tape & reel format is standard for automated assembly lines, while tube packaging is typical for manual or low-volume handling.

Q: Why are the onsemi parts marked as Obsolete?

A: Obsolete status indicates these parts are no longer manufactured or supported by onsemi. While existing inventory may be available, long-term supply cannot be guaranteed. New designs should prioritize Active status parts such as CD74ACT646M96.

Q: Can MC74ACT646DWR2G replace MC74ACT646DWG?

A: Yes. Both are onsemi equivalents with identical electrical specifications. The primary difference is packaging format (tape & reel versus unspecified), which does not affect functional compatibility.