SMAJ85A-TP Equivalent & Substitute Parts

Part Overview

The SMAJ85A-TP is a unidirectional Transient Voltage Suppressor (TVS) diode manufactured by Micro Commercial Co, designed for general-purpose transient voltage protection in surface-mount applications. This component operates with an 85V reverse standoff voltage and provides 137V maximum clamping voltage at peak pulse current. The part is Active status and ROHS3 compliant, making it suitable for modern electronic designs requiring transient suppression in the 85V protection class.

Equivalent and substitute parts are identified based on matching electrical performance parameters: reverse standoff voltage, breakdown voltage, clamping voltage, peak pulse current, and power dissipation capability. Mechanical compatibility is ensured through identical or functionally equivalent package specifications (DO-214AC/SMA form factor).

Substiute Parts

SMAJ85A-TP

Micro Commercial CoIn Stock: 5742SMAJ85A-TP Datasheet

Current PartRFQ

SMAJ85A

MDDIn Stock: 36947SMAJ85A Datasheet

DirectRFQ

SMAJ85A

MDDIn Stock: 36947SMAJ85A Datasheet

DirectRFQ

SMAJ85A-13-F

Diodes IncorporatedIn Stock: 12439SMAJ85A-13-F Datasheet

DirectRFQ

SMA6J85A-TR

STMicroelectronicsIn Stock: 30157SMA6J85A-TR Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts are classified into two categories based on electrical parameter alignment:

Direct Equivalents maintain identical electrical specifications across all critical parameters: reverse standoff voltage (85V), breakdown voltage (94.4V), clamping voltage (137V), and peak pulse current (2.9A at 10/1000µs). These parts are interchangeable at the circuit level with no design modifications required. Direct equivalents include SMAJ85A (MDD) and SMAJ85A-13-F (Diodes Incorporated).

Similar Substitutes share the same reverse standoff voltage (85V) and package form factor but differ in secondary electrical characteristics. The SMA6J85A-TR (STMicroelectronics) maintains 85V standoff voltage and DO-214AC/SMA packaging but operates at higher peak pulse current (22.5A at 8/20µs) and higher power dissipation (600W), with a slightly elevated clamping voltage (146V). This part functions as a substitute in applications where higher transient current capacity is acceptable or beneficial.

Substitution eligibility is determined by: (1) matching reverse standoff voltage class, (2) compatible package/case specification, (3) clamping voltage within acceptable circuit tolerance, and (4) peak pulse current rating meeting or exceeding circuit requirements.

Parameter Comparison

Engineering Selection Recommendations

SMAJ85A (MDD) and SMAJ85A-13-F (Diodes Incorporated) are direct electrical equivalents to SMAJ85A-TP. Both maintain identical reverse standoff voltage, breakdown voltage, clamping voltage, and peak pulse current specifications. Selection between these direct equivalents is determined by availability, lead time, and supply chain requirements. Both are Active status products with ROHS3 compliance and unlimited moisture sensitivity rating. The operating temperature range for SMAJ85A (MDD) is -50 to 150°C, which is narrower than the original part's -55 to 175°C range; SMAJ85A-13-F maintains -55 to 150°C, providing better low-temperature performance than MDD but not matching the upper temperature limit of the original.

SMA6J85A-TR (STMicroelectronics) is a similar substitute suitable for applications where higher transient current handling is required or acceptable. This part maintains the 85V reverse standoff voltage and DO-214AC/SMA package compatibility but provides 22.5A peak pulse current (versus 2.9A) and 600W power dissipation (versus 400W). The clamping voltage is 146V, which is 9V higher than the original specification. This part is appropriate for circuits where the elevated clamping voltage does not exceed system tolerance and where higher transient current capacity provides design margin. Operating temperature range matches the original at -55 to 175°C.

All substitute parts carry ROHS3 compliance and are classified as Active products, ensuring regulatory alignment and continued manufacturer support.

Frequently Asked Questions (FAQ)

Q: Can SMAJ85A (MDD) be used as a direct replacement for SMAJ85A-TP?

A: Yes. SMAJ85A (MDD) is a direct electrical equivalent with identical reverse standoff voltage (85V), breakdown voltage (94.4V), clamping voltage (137V), and peak pulse current (2.9A). Both use DO-214AC/SMA packaging. The operating temperature range for MDD is -50 to 150°C, which is narrower than the original -55 to 175°C specification. Verify that your application does not require operation below -50°C or above 150°C.

Q: What is the difference between SMAJ85A-13-F and SMAJ85A-TP?

A: SMAJ85A-13-F (Diodes Incorporated) is a direct electrical equivalent with matching reverse standoff voltage, breakdown voltage, clamping voltage, and peak pulse current. The primary difference is the operating temperature range: SMAJ85A-13-F operates from -55 to 150°C, while SMAJ85A-TP operates from -55 to 175°C. If your circuit requires operation above 150°C, SMAJ85A-TP or SMA6J85A-TR are required.

Q: When should SMA6J85A-TR be used instead of SMAJ85A-TP?

A: SMA6J85A-TR is appropriate when the circuit experiences transient currents exceeding 2.9A or when higher power dissipation capability (600W versus 400W) is beneficial for design margin. Both parts maintain 85V reverse standoff voltage and DO-214AC/SMA packaging. The clamping voltage is 146V (9V higher than SMAJ85A-TP). Verify that the elevated clamping voltage is acceptable for your circuit protection requirements before substitution.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. SMAJ85A (MDD), SMAJ85A-13-F (Diodes Incorporated), and SMA6J85A-TR (STMicroelectronics) are all ROHS3 compliant with unlimited moisture sensitivity rating (MSL 1), matching the original SMAJ85A-TP specification.

Q: What is the significance of the DO-214AC/SMA package specification?

A: DO-214AC and SMA refer to the same surface-mount package form factor. All listed substitute parts use this identical package, ensuring mechanical and electrical compatibility on printed circuit boards without layout modifications.

Q: Can SMAJ85A-TP be used in high-temperature applications above 150°C?

A: SMAJ85A-TP is rated for operation up to 175°C. SMAJ85A (MDD) is limited to 150°C, and SMAJ85A-13-F is limited to 150°C. For applications requiring sustained operation above 150°C, use SMAJ85A-TP or SMA6J85A-TR, both rated to 175°C.