SN74AS640DWG4 Equivalent & Substitute Parts

Part Overview

The SN74AS640DWG4 is a Logic Transceiver, Inverting component manufactured by Texas Instruments in the 74AS series. This device functions as a 1-element, 8-bit inverting transceiver with 3-state output capability, housed in a 20-SOIC surface mount package. The part is classified as Obsolete, making identification of functionally compatible alternatives necessary for ongoing design support and procurement planning. The device operates within a 4.5V to 5.5V supply voltage range and is rated for 0°C to 70°C operating temperature.

Substiute Parts

SN74AS640DWG4

Texas InstrumentsIn Stock: 1096SN74AS640DWG4 Datasheet

Current PartRFQ

SN74AS641DW

Texas InstrumentsIn Stock: 1063SN74AS641DW Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SN74AS640DWG4 is determined by the following critical parameters:

Mandatory Matching Parameters:

• Manufacturer Series: 74AS
• Number of Elements: 1
• Number of Bits per Element: 8
• Package / Case: 20-SOIC (0.295", 7.50mm Width)
• Mounting Type: Surface Mount
• Voltage - Supply: 4.5V ~ 5.5V
• Operating Temperature: 0°C ~ 70°C (TA)

Allowable Variation Parameters:

• Logic Type: Transceiver variants (Inverting or Non-Inverting)
• Output Type: 3-State or Open Collector configurations
• Current - Output High, Low: Within device capability specifications
• Product Status: Active status preferred for ongoing availability

The SN74AS641DW qualifies as a substitute based on matching all mandatory parameters while offering an alternative logic configuration (Non-Inverting) and output type (Open Collector) within the same 74AS series and package footprint.

Parameter Comparison

Engineering Selection Recommendations

The SN74AS641DW is available as an Active product from Texas Instruments, providing supply continuity for designs currently using the Obsolete SN74AS640DWG4. Both parts maintain identical compliance certifications (ROHS3 Compliant, REACH Unaffected) and share the same electrical operating parameters and package footprint.

The primary functional difference between these parts is the logic configuration: the SN74AS640DWG4 provides inverting logic with 3-state output, while the SN74AS641DW provides non-inverting logic with open collector output. Selection between these alternatives depends on the specific logic inversion and output drive requirements of the application circuit.

Frequently Asked Questions (FAQ)

Q: Can the SN74AS641DW directly replace the SN74AS640DWG4 without circuit modification?

A: Direct pin-for-pin replacement is possible due to identical package and pinout within the 20-SOIC footprint. However, functional compatibility requires evaluation of the logic inversion difference (inverting vs. non-inverting) and output type difference (3-state vs. open collector) in the context of the application circuit design.

Q: Are there electrical parameter differences between these parts?

A: Both parts operate within the same supply voltage range (4.5V ~ 5.5V) and temperature range (0°C ~ 70°C). The output low current specification is identical at 64mA. The SN74AS640DWG4 specifies 15mA output high current, while the SN74AS641DW does not specify output high current due to its open collector output configuration.

Q: What is the significance of the Obsolete status for the SN74AS640DWG4?

A: Obsolete status indicates the part is no longer in active production. The SN74AS641DW, with Active status, represents the recommended alternative for new designs and ongoing procurement requirements.

Q: Are both parts RoHS compliant?

A: Yes, both the SN74AS640DWG4 and SN74AS641DW are ROHS3 Compliant with Moisture Sensitivity Level 1 (Unlimited), meeting current environmental and reliability standards.

Q: What packaging format is available for the SN74AS641DW?

A: The SN74AS641DW is supplied in Tube packaging, maintaining the same 20-SOIC surface mount package configuration as the original part.