SN74LS645NG4 Equivalent & Substitute Parts

Part Overview

The SN74LS645NG4 is a non-inverting transceiver IC with 1 element, 8 bits per element, and 3-state output capability. This component is designed for bidirectional data bus applications requiring controlled signal transmission and reception. The SN74LS645NG4 is currently discontinued at DiGi Electronics, making identification of equivalent and substitute parts essential for ongoing design support and production continuity.

Substiute Parts

SN74LS645NG4

Texas InstrumentsIn Stock: 889SN74LS645NG4 Datasheet

Current PartRFQ

SN74LS645N

Texas InstrumentsIn Stock: 15261SN74LS645N Datasheet

MFR RecommendedRFQ

SN74LS245N

Texas InstrumentsIn Stock: 5252SN74LS245N Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the SN74LS645NG4 is determined by strict equivalence across 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: 15mA, 24mA
• Voltage - Supply: 4.75V ~ 5.25V
• Operating Temperature: 0°C ~ 70°C (TA)
• Package / Case: 20-DIP (0.300", 7.62mm)
• Mounting Type: Through Hole

Two substitute parts meet these criteria: SN74LS645N (manufacturer recommended) and SN74LS245N (parametric equivalent). Both parts share identical electrical specifications and mechanical packaging with the main part number.

Parameter Comparison

Engineering Selection Recommendations

The SN74LS645N is the manufacturer-recommended substitute for the discontinued SN74LS645NG4. Both parts carry identical part number bases (74LS645) and share all critical electrical and mechanical specifications. The SN74LS645N is currently in active production status with substantial inventory availability (15,245 pcs), ensuring supply chain continuity.

The SN74LS245N serves as a parametric equivalent, meeting all electrical and mechanical requirements specified for the main part. This part is also in active production status with adequate inventory (5,200 pcs). Selection between SN74LS645N and SN74LS245N depends on design-specific requirements beyond the provided parameters.

Both substitute parts maintain ROHS3 compliance and are suitable for applications requiring non-inverting transceiver functionality in 20-DIP through-hole packages.

Frequently Asked Questions (FAQ)

Q: Can SN74LS645N directly replace SN74LS645NG4 in existing designs?

A: Yes. The SN74LS645N shares identical electrical specifications (15mA/24mA output current, 4.75V–5.25V supply voltage, 0°C–70°C operating temperature) and mechanical packaging (20-DIP, 0.300" pitch, through-hole mounting). No design modifications are required.

Q: What is the difference between SN74LS645N and SN74LS245N?

A: Both parts meet identical electrical and mechanical parameters for transceiver functionality. The primary difference is the base product number designation (74LS645 versus 74LS245). Both are parametrically equivalent for the specified application.

Q: Are the substitute parts RoHS compliant?

A: Yes. Both SN74LS645N and SN74LS245N are ROHS3 compliant, matching the compliance status of the original SN74LS645NG4.

Q: What packaging options are available for the substitute parts?

A: Both substitute parts are supplied in 20-DIP through-hole packages with 0.300" (7.62mm) pitch. This matches the original part's mechanical specifications.

Q: Is there a difference in moisture sensitivity between the main part and substitutes?

A: The SN74LS645NG4 carries MSL Level 1 (Unlimited). The substitute parts (SN74LS645N and SN74LS245N) are listed as Not Applicable for MSL, indicating no moisture sensitivity restrictions.