SMCJ28 Equivalent & Substitute Parts Reference

Part Overview

The SMCJ28 is a unidirectional transient voltage suppressor (TVS) diode manufactured by Taiwan Semiconductor Corporation. This surface mount component operates at 28V reverse standoff voltage with 1500W peak pulse power rating and is designed for general-purpose transient protection applications. The part is active in production status with full RoHS3 compliance and unlimited moisture sensitivity level (MSL 1). Substitute parts are identified based on matching electrical performance parameters and mechanical compatibility within the DO-214AB (SMC) package form factor.

Substiute Parts

SMCJ28

Taiwan Semiconductor CorporationIn Stock: 4132SMCJ28 Datasheet

Current PartRFQ

SMCJ28A

MeritekIn Stock: 23149SMCJ28A Datasheet

SimilarRFQ

SMCJ28A

MeritekIn Stock: 23149SMCJ28A Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SMCJ28 are qualified based on the following electrical and mechanical criteria:

Mandatory Matching Parameters:

• Voltage - Reverse Standoff (Typ): 28V
• Voltage - Breakdown (Min): 31.1V
• Current - Peak Pulse (10/1000µs): within acceptable range for application
• Power - Peak Pulse: 1500W (1.5kW)
• Package / Case: DO-214AB (SMC)
• Mounting Type: Surface Mount
• Type: Zener
• Unidirectional Channels: 1
• Operating Temperature Range: -55°C to 150°C

Allowable Variation:

• Voltage - Clamping (Max) @ Ipp: may vary within design tolerance
• Current - Peak Pulse (10/1000µs): may vary within acceptable operational limits

The SMCJ28A from Meritek qualifies as a substitute based on identical reverse standoff voltage, breakdown voltage, power rating, package type, and operating temperature range. Clamping voltage and peak pulse current variations remain within acceptable parameters for general-purpose transient protection applications.

Parameter Comparison

Engineering Selection Recommendations

Both the SMCJ28 and SMCJ28A meet the core electrical and mechanical requirements for 28V transient voltage suppression applications. Selection between these parts is based on the following factors:

SMCJ28 (Taiwan Semiconductor Corporation):

• Primary choice when clamping voltage specification of 50V maximum is required
• 4,099 units currently in stock
• Established production status with active availability

SMCJ28A (Meritek):

• Alternative when lower clamping voltage of 45.4V is acceptable
• Higher peak pulse current capability (33.04A vs. 31A)
• 23,100 units currently in stock, indicating higher availability
• Identical compliance certifications (RoHS3, REACH Unaffected)

Both parts maintain identical reverse standoff voltage (28V), breakdown voltage (31.1V), power rating (1500W), operating temperature range (-55°C to 150°C), and package form factor (DO-214AB SMC). Both are RoHS3 compliant and REACH unaffected. Selection should be based on specific clamping voltage requirements and inventory availability for your application timeline.

Frequently Asked Questions (FAQ)

Q: Can SMCJ28A replace SMCJ28 in all applications?

A: SMCJ28A qualifies as a substitute where the lower clamping voltage of 45.4V (versus 50V) is acceptable for the circuit design. Both parts share identical reverse standoff voltage, breakdown voltage, power rating, and operating temperature range. Verify that the 4.6V reduction in maximum clamping voltage does not impact circuit protection requirements.

Q: What is the significance of the voltage parameters in TVS diode selection?

A: Reverse standoff voltage (28V) determines the normal operating threshold. Breakdown voltage (31.1V) defines the point at which the diode begins conducting. Clamping voltage (50V for SMCJ28, 45.4V for SMCJ28A) represents the maximum voltage across the diode during transient suppression. All three parameters must be compatible with the protected circuit.

Q: Are both parts mechanically compatible?

A: Yes. Both SMCJ28 and SMCJ28A use the DO-214AB (SMC) surface mount package. They are pin-compatible and suitable for identical PCB layouts and reflow soldering processes.

Q: What compliance certifications apply to both parts?

A: Both parts are RoHS3 compliant and REACH unaffected. Moisture sensitivity level is MSL 1 (unlimited) for both, indicating no special storage or handling requirements.

Q: How do the peak pulse current ratings differ?

A: SMCJ28 is rated at 31A peak pulse current, while SMCJ28A is rated at 33.04A. Both maintain the same 1500W power dissipation. The higher current rating of SMCJ28A provides additional margin in high-current transient scenarios.

Q: What is the series designation SMCJ?

A: SMCJ is the series designation for both parts, indicating they belong to the same product family of surface mount TVS diodes with similar electrical characteristics and package specifications.