SMAJ45C Equivalent & Substitute Parts

Part Overview

The SMAJ45C is a transient voltage suppressor (TVS) diode manufactured by Littelfuse Inc., rated at 45V reverse standoff with a 76.34V maximum clamping voltage. This component is designed for general-purpose transient voltage suppression in surface-mount applications using the DO-214AC (SMA) package. The SMAJ45C is currently listed as obsolete, making equivalent substitute parts necessary for ongoing design support and procurement.

Substiute Parts

SMAJ45C

Littelfuse Inc.In Stock: 1201SMAJ45C Datasheet

Current PartRFQ

SMAJ45CA

MDDIn Stock: 6423SMAJ45CA Datasheet

MFR RecommendedRFQ

SMAJ45CA

MDDIn Stock: 6423SMAJ45CA Datasheet

MFR RecommendedRFQ

SMAJ45CA-13-F

Diodes IncorporatedIn Stock: 5136SMAJ45CA-13-F Datasheet

MFR RecommendedRFQ

SMAJ45CA-TP

Micro Commercial CoIn Stock: 5938SMAJ45CA-TP Datasheet

MFR RecommendedRFQ

SMAJ45CAE3/TR13

Microchip TechnologyIn Stock: 815SMAJ45CAE3/TR13 Datasheet

MFR RecommendedRFQ

SMAJ45CE3/TR13

Microchip TechnologyIn Stock: 1004SMAJ45CE3/TR13 Datasheet

MFR RecommendedRFQ

TV04A450JB-G

Comchip TechnologyIn Stock: 1101TV04A450JB-G Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SMAJ45C is determined by the following critical parameters:

• Voltage - Reverse Standoff (Typ): 45V (all substitutes match)
• Voltage - Breakdown (Min): 47.39V minimum (substitutes range 50V, which exceeds minimum)
• Package / Case: DO-214AC, SMA (all substitutes use identical package)
• Bidirectional Channels: 1 (all substitutes are single-channel)
• Type: Zener (all substitutes are Zener type)
• RoHS Status: ROHS3 Compliant (all substitutes comply)
• Moisture Sensitivity Level: 1 (Unlimited) (all substitutes match)

Substitute parts are grouped into two categories based on clamping voltage performance:

Group A (72.7V Clamping): SMAJ45CA, SMAJ45CA-13-F, SMAJ45CA-TP, TV04A450JB-G

• Clamping voltage: 72.7V (lower than original 76.34V)
• Peak pulse current: 5.5A
• Peak pulse power: 400W

Group B (Higher Performance): SMAJ45CAE3/TR13, SMAJ45CE3/TR13

• SMAJ45CAE3/TR13: 72.7V clamping, 6.9A peak pulse, 500W power
• SMAJ45CE3/TR13: 80.3V clamping, 6.2A peak pulse, 500W power

Parameter Comparison

Engineering Selection Recommendations

All substitute parts listed are active products with ROHS3 compliance and MSL 1 rating, ensuring regulatory compliance and manufacturing availability.

For applications requiring direct electrical equivalence with the original SMAJ45C clamping voltage specification (76.34V), the SMAJ45CE3/TR13 provides the closest match at 80.3V clamping voltage while maintaining the same 45V reverse standoff rating and operating temperature range of -65°C to 150°C.

For general-purpose applications where clamping voltage tolerance permits, Group A substitutes (SMAJ45CA, SMAJ45CA-13-F, SMAJ45CA-TP, TV04A450JB-G) offer equivalent performance at 72.7V clamping with active product status and broad manufacturer availability.

The SMAJ45CAE3/TR13 provides enhanced transient handling capability with 6.9A peak pulse current and 500W power rating while maintaining 72.7V clamping voltage, suitable for applications requiring higher transient energy dissipation.

Temperature range considerations: SMAJ45CA-TP extends to -55°C to 175°C (TA), providing the widest ambient temperature range among substitutes. SMAJ45CAE3/TR13 and SMAJ45CE3/TR13 maintain the original -65°C to 150°C (TJ) range.

Frequently Asked Questions (FAQ)

Q: Can SMAJ45CA be used as a direct replacement for SMAJ45C?

A: SMAJ45CA is functionally compatible for general-purpose transient voltage suppression. Both share identical 45V reverse standoff voltage, 5.5A peak pulse current, 400W power rating, and DO-214AC (SMA) package. The primary difference is clamping voltage: SMAJ45CA clamps at 72.7V versus SMAJ45C at 76.34V. This 3.64V difference must be evaluated against circuit protection requirements.

Q: What is the difference between Group A and Group B substitutes?

A: Group A substitutes (SMAJ45CA, SMAJ45CA-13-F, SMAJ45CA-TP, TV04A450JB-G) maintain 72.7V clamping voltage and 5.5A peak pulse current. Group B substitutes offer enhanced performance: SMAJ45CAE3/TR13 provides 6.9A peak pulse and 500W power; SMAJ45CE3/TR13 provides 80.3V clamping voltage and 6.2A peak pulse with 500W power. Selection depends on transient energy requirements and clamping voltage tolerance.

Q: Are all substitutes available in the same package?

A: Yes. All substitute parts use the DO-214AC (SMA) surface-mount package, ensuring mechanical and electrical compatibility with the original SMAJ45C footprint.

Q: Which substitute has the closest clamping voltage to the original SMAJ45C?

A: SMAJ45CE3/TR13 provides the closest match at 80.3V clamping voltage, compared to the original 76.34V. This represents a 3.96V increase. All other Group A substitutes clamp at 72.7V, which is 3.64V lower than the original.

Q: Do all substitutes meet RoHS compliance?

A: Yes. All listed substitute parts are ROHS3 compliant with MSL 1 (Unlimited) moisture sensitivity rating, matching the original SMAJ45C specifications.

Q: What temperature range should I consider when selecting a substitute?

A: The original SMAJ45C operates from -65°C to 150°C (TJ). Most substitutes maintain this range. SMAJ45CA operates from -50°C to 150°C (TJ), which is 15°C narrower at the low end. SMAJ45CA-TP extends to -55°C to 175°C (TA), providing the widest range. Verify your application's temperature requirements before selection.

Q: Can SMAJ45CE3/TR13 be used in place of SMAJ45C despite higher clamping voltage?

A: SMAJ45CE3/TR13 is electrically compatible with identical 45V reverse standoff voltage and package. The 80.3V clamping voltage is 3.96V higher than the original 76.34V. This higher clamping voltage may allow greater transient overshoot in the protected circuit. Circuit analysis is required to confirm acceptability for your specific application.