SMAJ33C Equivalent & Substitute Parts

Part Overview

The SMAJ33C is a transient voltage suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose overvoltage protection in surface-mount applications. This component features a 33V reverse standoff voltage, 55.97V maximum clamping voltage, and 7.5A peak pulse current capability in a DO-214AC (SMA) package. The SMAJ33C is classified as obsolete, making equivalent substitute parts necessary for ongoing design support and procurement.

Substiute Parts

SMAJ33C

Littelfuse Inc.In Stock: 1198SMAJ33C Datasheet

Current PartRFQ

SMAJ33CA

Good-Ark SemiconductorIn Stock: 26961SMAJ33CA Datasheet

DirectRFQ

SZ1SMA33CAT3G

onsemiIn Stock: 30304SZ1SMA33CAT3G Datasheet

MFR RecommendedRFQ

SMAJ33CA

Good-Ark SemiconductorIn Stock: 26961SMAJ33CA Datasheet

DirectRFQ

SMAJ33CA-13-F

Diodes IncorporatedIn Stock: 5146SMAJ33CA-13-F Datasheet

MFR RecommendedRFQ

SMAJ33CA-TP

Micro Commercial CoIn Stock: 3133SMAJ33CA-TP Datasheet

MFR RecommendedRFQ

SMAJ33CA-TR

STMicroelectronicsIn Stock: 18099SMAJ33CA-TR Datasheet

MFR RecommendedRFQ

SMAJ33CAE3/TR13

Microchip TechnologyIn Stock: 5208SMAJ33CAE3/TR13 Datasheet

MFR RecommendedRFQ

SMAJ33CE3/TR13

Microchip TechnologyIn Stock: 1019SMAJ33CE3/TR13 Datasheet

MFR RecommendedRFQ

TV04A330JB-G

Comchip TechnologyIn Stock: 718TV04A330JB-G Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SMAJ33C are qualified based on the following critical parameters:

• Voltage - Reverse Standoff: Must be 33V (±tolerance)
• Package / Case: Must be DO-214AC or SMA equivalent
• Bidirectional Channels: Must be 1 (single channel)
• Type: Must be Zener TVS diode
• Mounting Type: Must be Surface Mount
• RoHS Compliance: Must maintain ROHS3 Compliant status
• Moisture Sensitivity Level: Must be 1 (Unlimited)

Substitute parts are grouped into two categories: direct equivalents with matching clamping voltage specifications (53.3V range) and variants with different clamping voltages or peak pulse ratings that maintain core voltage protection characteristics.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitutes (Direct Equivalents)

SMAJ33CA (Good-Ark Semiconductor), SMAJ33CA-13-F (Diodes Incorporated), SMAJ33CA-TP (Micro Commercial Co), and TV04A330JB-G (Comchip Technology) are direct functional equivalents with matching 33V standoff voltage, 53.3V clamping voltage, and 7.5A peak pulse current. All are active products with ROHS3 compliance and MSL 1 rating. These parts are suitable for direct replacement in applications where the original SMAJ33C specifications are required.

Automotive-Grade Alternative

SZ1SMA33CAT3G (onsemi) provides an automotive-qualified option with AEC-Q101 certification. This part matches the core electrical specifications of direct equivalents while extending the operating temperature range to -65°C, matching the original SMAJ33C lower temperature limit. This option is appropriate for automotive or high-reliability applications.

Enhanced Performance Variants

SMAJ33CAE3/TR13 (Microchip Technology) offers increased peak pulse current (9.4A) and power dissipation (500W) while maintaining the 33V standoff and 53.3V clamping voltage. SMAJ33CE3/TR13 (Microchip Technology) provides 59V clamping voltage with 8.5A peak pulse current and 500W power rating. These variants are suitable for applications requiring higher transient energy absorption.

Higher Performance Alternative

SMAJ33CA-TR (STMicroelectronics) features significantly higher peak pulse current (33A at 8/20µs) and maintains 33V standoff voltage. The 69.7V clamping voltage represents a higher protection threshold. This part is appropriate for applications with more severe transient conditions.

Frequently Asked Questions (FAQ)

Q: Can SMAJ33CA directly replace SMAJ33C?

A: Yes. SMAJ33CA maintains the same 33V reverse standoff voltage, DO-214AC package, and 7.5A peak pulse current. The 53.3V clamping voltage is lower than the original 55.97V specification but remains within acceptable protection parameters for 33V standoff applications. Verify application requirements before substitution.

Q: What is the difference between SMAJ33CA and SZ1SMA33CAT3G?

A: Both parts share identical electrical specifications (33V standoff, 53.3V clamping, 7.5A peak pulse). SZ1SMA33CAT3G includes automotive-grade qualification (AEC-Q101) and extends the lower operating temperature limit to -65°C, matching the original SMAJ33C. Choose SZ1SMA33CAT3G for automotive or temperature-critical applications.

Q: Why does SMAJ33CA-TR have different specifications?

A: SMAJ33CA-TR is a higher-performance variant designed for applications requiring greater transient energy absorption. It maintains the 33V standoff voltage but increases peak pulse current to 33A (8/20µs) and clamping voltage to 69.7V. Use this part only if your application requires enhanced protection beyond standard 7.5A specifications.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All listed substitute parts maintain ROHS3 compliance and MSL 1 (Unlimited) moisture sensitivity rating, matching the original SMAJ33C environmental specifications.

Q: What packaging options are available?

A: All substitute parts use DO-214AC (SMA) surface-mount packaging, identical to the original SMAJ33C. Tape & Reel (TR) and Cut Tape (CT) packaging options are available from various manufacturers for production quantities.

Q: Can I use SMAJ33CAE3/TR13 or SMAJ33CE3/TR13 as direct replacements?

A: These Microchip Technology parts are compatible substitutes with enhanced specifications. SMAJ33CAE3/TR13 increases peak pulse current to 9.4A and power to 500W while maintaining 53.3V clamping. SMAJ33CE3/TR13 raises clamping voltage to 59V with 8.5A current and 500W power. Both extend operating temperature to -65°C. Use these parts when higher transient energy handling is beneficial or required.