SN54123J Equivalent & Substitute Parts

Part Overview

The SN54123J is a retriggerable monostable multivibrator manufactured by Texas Instruments, designed for logic circuit applications requiring precision timing and pulse generation. This 16-pin CDIP package device operates across military-grade temperature ranges (-55°C to 125°C) and is classified as Active product status. The SN54123J contains two independent monostable circuits with a propagation delay of 30 ns and is RoHS3 compliant.

Equivalent and substitute parts are identified when component availability is limited, procurement lead times are extended, or design flexibility permits selection from functionally compatible alternatives within the same logic family. Substitutes must maintain compatibility across critical electrical parameters including supply voltage ranges, output current specifications, logic type, and circuit count.

Substiute Parts

SN54123J

Texas InstrumentsIn Stock: 1431SN54123J Datasheet

Current PartRFQ

SN74123N

Texas InstrumentsIn Stock: 2475SN74123N Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SN54123J is determined by strict alignment of the following critical parameters:

Functional Compatibility Criteria:

• Logic Type: Must be Monostable multivibrator
• Independent Circuits: Must equal 2
• Schmitt Trigger Input: Must match (No)
• Package Type: Must be 16-pin DIP configuration with 0.300" (7.62mm) pitch

Electrical Compatibility Criteria:

• Supply Voltage Range: Must overlap or be contained within 4.5 V ~ 5.5 V
• Output Current Specifications: Must support minimum 16 mA (High) and 800 µA (Low)
• Propagation Delay: Must be equal to or faster than 30 ns

Environmental & Compliance Criteria:

• Mounting Type: Through Hole required
• RoHS Status: ROHS3 Compliant
• Product Status: Active

The SN74123N qualifies as a direct substitute based on these parameters. Both devices share identical circuit topology, pin configuration, and functional specifications. Differences in operating temperature range and propagation delay represent performance variations within acceptable substitution boundaries for most applications.

Parameter Comparison

Engineering Selection Recommendations

SN54123J Selection Criteria:

• Required for military-grade temperature operation (-55°C to 125°C)
• Applications demanding extended supply voltage tolerance (4.5 V ~ 5.5 V)
• Systems requiring 16 mA output drive capability at logic high state
• CDIP package preference for specific PCB layouts

SN74123N Selection Criteria:

• Commercial-grade temperature range applications (0°C to 70°C)
• Faster propagation delay (22 ns) beneficial for timing-critical circuits
• Narrower supply voltage specification (4.75 V ~ 5.25 V) acceptable in regulated power systems
• 16 mA output drive capability at logic low state
• 7400 series product line integration
• Higher inventory availability (2438 Pcs vs 1355 Pcs)

Both parts maintain Active product status and ROHS3 compliance, ensuring long-term availability and regulatory conformance. Selection between these devices depends on operating environment specifications and application temperature requirements rather than functional capability.

Frequently Asked Questions (FAQ)

Q: Can SN74123N directly replace SN54123J in all applications?

A: Direct replacement is possible only when the application operates within the SN74123N's temperature range (0°C to 70°C) and supply voltage range (4.75 V to 5.25 V). The SN54123J is required for military-grade temperature operation (-55°C to 125°C) or extended supply voltage tolerance (4.5 V to 5.5 V).

Q: What is the difference in propagation delay between these parts?

A: The SN74123N has a propagation delay of 22 ns compared to the SN54123J's 30 ns. The substitute part is 8 ns faster, which is generally beneficial for timing-critical applications but must be verified against circuit timing requirements.

Q: Are the output current specifications interchangeable?

A: No. The SN54123J provides 16 mA at logic high and 800 µA at logic low, while the SN74123N provides 800 µA at logic high and 16 mA at logic low. Circuit designs must accommodate these different output drive characteristics.

Q: Are both parts pin-compatible?

A: Yes. Both devices use 16-pin DIP packages with 0.300" (7.62mm) pitch. The CDIP and PDIP package variants are mechanically and electrically compatible for through-hole PCB mounting.

Q: What supply voltage range is safe for both parts?

A: The overlapping safe operating range is 4.75 V to 5.25 V. This range satisfies both the SN54123J (4.5 V ~ 5.5 V) and SN74123N (4.75 V ~ 5.25 V) specifications.

Q: Are both parts RoHS compliant?

A: Yes. Both the SN54123J and SN74123N are ROHS3 compliant, meeting environmental and regulatory requirements for electronic component manufacturing and use.

Q: Which part should be selected for new designs?

A: Selection depends on environmental requirements. For commercial applications with standard temperature ranges, the SN74123N is appropriate. For military, aerospace, or extended-temperature applications, the SN54123J is required.