74ACQ646SC Equivalent & Substitute Parts

Part Overview

The 74ACQ646SC is a non-inverting transceiver IC manufactured by onsemi, featuring 1 element with 8 bits per element and 3-state output capability. This 24-SOP surface mount device operates across a 2V to 6V supply voltage range and is rated for -40°C to 85°C operating temperature. The product is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement continuity.

Key Parameters

Parameter	Value
Manufacturer Part Number	74ACQ646SC
Manufacturer	onsemi
Logic Type	Transceiver, Non-Inverting
Number of Elements	1
Number of Bits per Element	8
Output Type	3-State
Current - Output High, Low	24mA, 24mA
Voltage - Supply	2V ~ 6V
Operating Temperature	-40°C ~ 85°C (TA)
Mounting Type	Surface Mount
Package / Case	24-SOIC (0.295", 7.50mm Width)
Product Status	Obsolete
Moisture Sensitivity Level (MSL)	1 (Unlimited)

Substitute Part Grouping Explanation

Substitution eligibility for the 74ACQ646SC is determined by the following critical parameters:

Logic Type: Transceiver, Non-Inverting
Number of Elements: 1
Number of Bits per Element: 8
Output Type: 3-State
Current - Output High, Low: 24mA, 24mA
Package / Case: 24-SOIC (0.295", 7.50mm Width)
Mounting Type: Surface Mount

Substitute parts must maintain identical electrical characteristics (output current, element configuration, bit width) and physical compatibility (24-SOIC package footprint). Voltage supply range and operating temperature may vary within acceptable design margins. All identified substitutes share the base product number 74AC646 and are manufactured by onsemi or Texas Instruments.

Parameter Comparison

Parameter	74ACQ646SC	MC74AC646DWR2G	MC74AC646DWG	CD74AC646M	CD74AC646M96
Manufacturer	onsemi	onsemi	onsemi	Texas Instruments	Texas Instruments
Logic Type	Transceiver, Non-Inverting	Transceiver, Non-Inverting	Transceiver, Non-Inverting	Transceiver, Non-Inverting	Transceiver, Non-Inverting
Number of Elements	1	1	1	1	1
Number of Bits per Element	8	8	8	8	8
Output Type	3-State	3-State	3-State	3-State	3-State
Current - Output High, Low	24mA, 24mA	24mA, 24mA	24mA, 24mA	24mA, 24mA	24mA, 24mA
Voltage - Supply	2V ~ 6V	2V ~ 6V	2V ~ 6V	1.5V ~ 5.5V	1.5V ~ 5.5V
Operating Temperature	-40°C ~ 85°C (TA)	-40°C ~ 85°C (TA)	-40°C ~ 85°C (TA)	-55°C ~ 125°C (TA)	-55°C ~ 125°C (TA)
Package / Case	24-SOIC	24-SOIC	24-SOIC	24-SOIC	24-SOIC
Mounting Type	Surface Mount	Surface Mount	Surface Mount	Surface Mount	Surface Mount
Product Status	Obsolete	Obsolete	Obsolete	Last Time Buy	Active
RoHS Status	Not specified	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
Moisture Sensitivity Level (MSL)	1 (Unlimited)	3 (168 Hours)	3 (168 Hours)	1 (Unlimited)	1 (Unlimited)

Engineering Selection Recommendations

All substitute parts maintain functional and electrical equivalence to the 74ACQ646SC based on core transceiver parameters. Selection should prioritize product status and compliance requirements:

CD74AC646M96 (Texas Instruments) is the preferred substitute, offering active product status with ROHS3 compliance and unlimited moisture sensitivity rating. This part provides the longest lifecycle support and broadest environmental compliance.

CD74AC646M (Texas Instruments) serves as an alternative with Last Time Buy status, suitable for applications where extended temperature range (-55°C to 125°C) provides design margin beyond the original 74ACQ646SC specification.

MC74AC646DWR2G and MC74AC646DWG (onsemi) maintain manufacturer continuity with ROHS3 compliance, though both carry obsolete product status. These parts are appropriate for designs requiring onsemi sourcing or existing supply chain relationships.

All substitutes are packaged in 24-SOIC form factor with identical footprint compatibility. Voltage supply ranges and operating temperatures of substitute parts encompass or exceed the original specification, ensuring functional compatibility in existing circuit designs.

Frequently Asked Questions (FAQ)

Q: Can I directly replace 74ACQ646SC with CD74AC646M96 without circuit modification?

A: Yes. Both parts share identical logic type, element configuration, bit width, output type, output current ratings, and 24-SOIC package footprint. The CD74AC646M96 supply voltage range (1.5V ~ 5.5V) and operating temperature range (-55°C ~ 125°C) encompass the original specification (2V ~ 6V, -40°C ~ 85°C).

Q: What is the difference between MC74AC646DWR2G and MC74AC646DWG?

A: Both are onsemi equivalents with identical electrical specifications. The primary difference is packaging: MC74AC646DWR2G is supplied in Cut Tape format, while MC74AC646DWG is supplied in Tube format. Functional performance and 24-SOIC package dimensions are identical.

Q: Why do some substitutes have different moisture sensitivity levels?

A: Moisture Sensitivity Level (MSL) reflects storage and handling requirements. The 74ACQ646SC carries MSL 1 (unlimited storage), while some substitutes carry MSL 3 (168-hour limit). This affects shelf life and reflow processing windows but does not impact electrical performance or circuit functionality.

Q: Are all substitutes ROHS3 compliant?

A: The Texas Instruments parts (CD74AC646M and CD74AC646M96) and onsemi substitutes (MC74AC646DWR2G and MC74AC646DWG) are explicitly ROHS3 compliant. The original 74ACQ646SC RoHS status is not specified in available documentation.

Q: Which substitute offers the longest product lifecycle?

A: CD74AC646M96 carries Active product status, indicating ongoing manufacturing and support. This part is recommended for new designs requiring extended component availability and supply chain stability.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message