74ACTQ543SC Equivalent & Substitute Parts

Part Overview

The 74ACTQ543SC is a non-inverting transceiver logic integrated circuit manufactured by onsemi, designed for 8-bit data transmission with 3-state output capability. This device operates within a 4.5V to 5.5V supply voltage range and is housed in a 24-SOP surface mount package. The product is currently classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing system support and new design implementations.

Substiute Parts

74ACTQ543SC

onsemiIn Stock: 76774ACTQ543SC Datasheet

Current PartRFQ

74ACT11245DW

Texas InstrumentsIn Stock: 75274ACT11245DW Datasheet

Parametric EquivalentRFQ

MC74ACT646DWG

onsemiIn Stock: 972MC74ACT646DWG Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 74ACTQ543SC is determined by strict parametric matching across the following critical criteria:

• 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: 4.5V ~ 5.5V
• Operating Temperature: -40°C ~ 85°C (TA)
• Mounting Type: Surface Mount
• Package / Case: 24-SOIC (0.295", 7.50mm Width)

All identified substitute parts meet these electrical and mechanical parameters, ensuring functional compatibility in applications currently utilizing the 74ACTQ543SC.

Parameter Comparison

Engineering Selection Recommendations

The 74ACT11245DW from Texas Instruments represents the primary substitute option, offering identical electrical and mechanical specifications while maintaining an active Last Time Buy product status. This part provides superior availability and compliance documentation, with confirmed ROHS3 compliance and MSL 1 rating.

The MC74ACT646DWG from onsemi serves as a secondary equivalent, matching all critical electrical parameters and package specifications. However, this part carries an obsolete product status classification and features an MSL 3 rating, requiring controlled moisture handling during storage and assembly compared to the MSL 1 rating of the primary substitute.

Both substitute parts maintain full parametric equivalence with the 74ACTQ543SC across supply voltage, output current, operating temperature range, and functional logic configuration, supporting direct replacement in existing circuit designs.

Frequently Asked Questions (FAQ)

Q: Can the 74ACT11245DW directly replace the 74ACTQ543SC in existing designs?

A: Yes. Both parts share identical electrical specifications (4.5V–5.5V supply, 24mA output current, -40°C to 85°C operating range), functional logic type (non-inverting transceiver, 8-bit, 3-state output), and package configuration (24-SOIC). Pin-to-pin compatibility is maintained.

Q: What is the difference between the two substitute parts?

A: The 74ACT11245DW maintains an active Last Time Buy status with ROHS3 compliance and MSL 1 rating. The MC74ACT646DWG is obsolete with MSL 3 rating, requiring controlled moisture exposure during handling and storage.

Q: Does package compatibility extend beyond physical dimensions?

A: The 24-SOIC package specification (0.295", 7.50mm width) is identical across all three parts, ensuring mechanical fit on PCBs designed for the 74ACTQ543SC. Pin count and spacing are equivalent.

Q: Are there compliance or certification differences between these parts?

A: The 74ACT11245DW carries ROHS3 compliance certification. Both substitute parts maintain REACH Unaffected status and EAR99 export classification, matching the original part's regulatory profile.

Q: What does MSL 3 rating mean for the MC74ACT646DWG?

A: MSL 3 indicates a 168-hour moisture sensitivity level, requiring storage in controlled humidity environments and limiting floor life after moisture exposure. The 74ACTQ543SC and 74ACT11245DW both carry MSL 1 (unlimited) ratings, eliminating these handling constraints.