1SMA40CAT3 Equivalent & Substitute Parts

Part Overview

The 1SMA40CAT3 is a bidirectional transient voltage suppressor (TVS) diode manufactured by onsemi in the DO-214AC (SMA) surface mount package. This component is rated for 40V reverse standoff voltage with a 64.5V maximum clamping voltage and 6.2A peak pulse current. The part is classified as obsolete, making equivalent substitutes necessary for new designs and ongoing production requirements. Substitute parts must maintain electrical compatibility across voltage ratings, clamping characteristics, and thermal performance while meeting current RoHS3 compliance standards.

Substiute Parts

1SMA40CAT3

onsemiIn Stock: 7581SMA40CAT3 Datasheet

Current PartRFQ

SMAJ40CA

Good-Ark SemiconductorIn Stock: 19908SMAJ40CA Datasheet

DirectRFQ

SMAJ40CA

Good-Ark SemiconductorIn Stock: 19908SMAJ40CA Datasheet

DirectRFQ

SMAJ40CA-TR

STMicroelectronicsIn Stock: 63124SMAJ40CA-TR Datasheet

DirectRFQ

SM4T47CAY

STMicroelectronicsIn Stock: 5380SM4T47CAY Datasheet

SimilarRFQ

SMA6J40CA-TR

STMicroelectronicsIn Stock: 70386SMA6J40CA-TR Datasheet

SimilarRFQ

SMAJ40CA-13-F

Diodes IncorporatedIn Stock: 18388SMAJ40CA-13-F Datasheet

SimilarRFQ

SMAJ40CA-TP

Micro Commercial CoIn Stock: 32122SMAJ40CA-TP Datasheet

SimilarRFQ

SMAJ40CAE3/TR13

Microchip TechnologyIn Stock: 5297SMAJ40CAE3/TR13 Datasheet

SimilarRFQ

TV04A400JB-G

Comchip TechnologyIn Stock: 1038TV04A400JB-G Datasheet

SimilarRFQ

TV04A400JB-HF

Comchip TechnologyIn Stock: 1072TV04A400JB-HF Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility is determined by strict electrical and mechanical parameter matching:

Primary Substitution Criteria:

• Voltage - Reverse Standoff (Typ): 40V
• Voltage - Breakdown (Min): 44.4V
• Package / Case: DO-214AC, SMA
• Mounting Type: Surface Mount
• Bidirectional Channels: 1
• Type: Zener

Acceptable Variation Ranges:

• Voltage - Clamping (Max) @ Ipp: 64.5V to 84V (higher clamping voltage acceptable for transient suppression)
• Current - Peak Pulse (10/1000µs): 5.6A to 48A (higher current rating acceptable)
• Power - Peak Pulse: 400W to 600W (higher power dissipation acceptable)
• Operating Temperature: -55°C to -65°C minimum; 150°C to 175°C maximum (extended ranges acceptable)

Parts are grouped into two categories: Direct Equivalents (matching clamping voltage and peak pulse current) and Similar Alternatives (matching core voltage parameters with higher performance ratings).

Parameter Comparison

Engineering Selection Recommendations

Direct Equivalents (Recommended Primary Substitutes):

SMAJ40CA (Good-Ark Semiconductor), SMAJ40CA-13-F (Diodes Incorporated), and TV04A400JB-G (Comchip Technology) provide electrical and thermal equivalence to the 1SMA40CAT3. All three maintain 40V reverse standoff, 44.4V minimum breakdown, 64.5V maximum clamping voltage, and 6.2A peak pulse current. All are active products with ROHS3 compliance. SMAJ40CA-TP (Micro Commercial Co) offers identical electrical performance with extended operating temperature range to 175°C. SMAJ40CAE3/TR13 (Microchip Technology) provides slightly elevated peak pulse current (7.8A) and power dissipation (500W) while maintaining the same voltage ratings and temperature range matching the original part.

Higher Performance Alternatives:

SMAJ40CA-TR (STMicroelectronics) and SM4T47CAY (STMicroelectronics) both feature 84V maximum clamping voltage and 27A peak pulse current, providing enhanced transient suppression capability. SMA6J40CA-TR (STMicroelectronics) offers the highest performance with 73.6V clamping voltage, 48A peak pulse current, and 600W power dissipation, with extended temperature range to 175°C. These alternatives are suitable for applications requiring higher surge current handling or improved thermal performance.

Thermal Considerations:

TV04A400JB-HF (Comchip Technology) features 71.4V clamping voltage with reduced peak pulse current (5.6A), suitable for applications with lower transient energy requirements. All substitute parts maintain the DO-214AC (SMA) surface mount package, ensuring mechanical compatibility.

Frequently Asked Questions (FAQ)

Q: Can SMAJ40CA-TR or SM4T47CAY be used as direct replacements for 1SMA40CAT3?

A: Yes. Both parts maintain the required 40V reverse standoff and 44.4V minimum breakdown voltage. The higher clamping voltage (84V) and peak pulse current (27A) provide enhanced protection without compromising circuit compatibility. The DO-214AC package ensures mechanical fit.

Q: What is the difference between SMAJ40CA and SMAJ40CA-TP?

A: Both parts are electrically identical with 40V standoff, 64.5V clamping, and 6.2A peak pulse current. SMAJ40CA-TP extends the operating temperature range to 175°C (versus 150°C), providing improved thermal margin for high-temperature applications.

Q: Is SMA6J40CA-TR suitable for this application?

A: Yes. SMA6J40CA-TR maintains the 40V reverse standoff and 44.4V breakdown voltage. The higher clamping voltage (73.6V), peak pulse current (48A), and power dissipation (600W) provide superior transient suppression. The extended temperature range to 175°C offers additional thermal headroom.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All listed substitute parts carry ROHS3 compliance certification. The original 1SMA40CAT3 is RoHS non-compliant, making compliant substitutes necessary for new designs and production.

Q: Does package compatibility affect substitution?

A: No. All substitute parts use the DO-214AC (SMA) surface mount package, ensuring direct PCB footprint compatibility with the original 1SMA40CAT3.

Q: Can TV04A400JB-HF replace 1SMA40CAT3 in all applications?

A: TV04A400JB-HF is electrically compatible with 40V standoff and 44.4V breakdown voltage. The slightly higher clamping voltage (71.4V) and lower peak pulse current (5.6A) are acceptable for most general-purpose transient suppression applications. Verify peak transient energy requirements for your specific circuit.