1SMA5949 Zener Diode Equivalent & Substitute Parts

Part Overview

The 1SMA5949 is an active-status Zener diode manufactured by Taiwan Semiconductor Corporation, rated for 100 V nominal Zener voltage with 1.5 W maximum power dissipation in a surface mount DO-214AC (SMA) package. This component is ROHS3 compliant and suitable for voltage regulation and protection applications in electronic circuits. Substitute parts are identified based on matching or exceeding electrical specifications while maintaining package compatibility and compliance certifications.

Substiute Parts

1SMA5949

Taiwan Semiconductor CorporationIn Stock: 8441SMA5949 Datasheet

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3SMAJ5949B-TP

Micro Commercial CoIn Stock: 144223SMAJ5949B-TP Datasheet

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SMAJ5949B-TP

Micro Commercial CoIn Stock: 1959SMAJ5949B-TP Datasheet

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SML4764A-E3/61

Vishay General Semiconductor - Diodes DivisionIn Stock: 18436SML4764A-E3/61 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 1SMA5949 are selected based on the following criteria:

Primary Matching Parameters:

• Zener voltage: 100 V nominal (±5% tolerance)
• Package type: DO-214AC (SMA) surface mount
• Mounting type: Surface mount
• Compliance: ROHS3 compliant, REACH unaffected
• Moisture sensitivity: MSL 1 (Unlimited)

Acceptable Variation Parameters:

• Power rating: Equal to or greater than 1.5 W
• Impedance: Equal to or less than 250 Ohms (lower impedance acceptable)
• Reverse leakage current: Equal to or less than 500 nA @ 76 V (lower leakage acceptable)
• Operating temperature range: Minimum -55°C to 150°C

Substitutes are grouped by power rating capability. Parts with higher power ratings (3 W) provide enhanced thermal performance for the same voltage specification. Parts with lower power ratings (1 W) are acceptable only when circuit power requirements do not exceed the lower rating.

Parameter Comparison

Engineering Selection Recommendations

Direct Replacement (Equivalent Function): SMAJ5949B-TP from Micro Commercial Co matches the 1SMA5949 specification exactly: 100 V nominal Zener voltage, 1.5 W power rating, 250 Ohms maximum impedance, and identical operating temperature range. Both parts are ROHS3 compliant with MSL 1 rating. This part is suitable for direct substitution in applications where the original specification must be maintained.

Enhanced Performance Substitute (Higher Power Rating): 3SMAJ5949B-TP from Micro Commercial Co provides the same 100 V Zener voltage and operating temperature range but with doubled power dissipation capability (3 W versus 1.5 W). This part is suitable for applications requiring improved thermal margin or higher power handling. Impedance and compliance specifications remain equivalent.

Lower Power Substitute (Reduced Thermal Load): SML4764A-E3/61 from Vishay General Semiconductor maintains the 100 V Zener voltage and ROHS3 compliance but with reduced power rating (1 W). This part is suitable only for applications where circuit power dissipation does not exceed 1 W. Impedance is specified at 350 Ohms maximum, which exceeds the original 250 Ohms specification. Operating temperature range is not specified for this part.

Selection Basis: All substitute parts maintain the critical electrical parameters: 100 V nominal Zener voltage, ±5% tolerance, DO-214AC (SMA) package, surface mount configuration, ROHS3 compliance, and MSL 1 moisture sensitivity rating. Selection among substitutes depends on circuit power requirements and thermal design constraints.

Frequently Asked Questions (FAQ)

Q: Can SMAJ5949B-TP be used as a direct replacement for 1SMA5949? A: Yes. SMAJ5949B-TP matches all critical specifications: 100 V Zener voltage, 1.5 W power rating, 250 Ohms impedance, -55 to 150°C operating temperature, DO-214AC package, and ROHS3 compliance. This part is functionally equivalent.

Q: What is the advantage of using 3SMAJ5949B-TP instead of the original 1SMA5949? A: 3SMAJ5949B-TP provides double the power dissipation capability (3 W versus 1.5 W) while maintaining identical Zener voltage and impedance specifications. This allows for improved thermal performance in high-power applications or provides additional design margin in existing circuits.

Q: Is SML4764A-E3/61 suitable for all applications using 1SMA5949? A: No. SML4764A-E3/61 has a reduced power rating of 1 W, which is lower than the original 1.5 W specification. This part is suitable only for applications where circuit power dissipation does not exceed 1 W. Additionally, impedance is specified at 350 Ohms, exceeding the original 250 Ohms maximum.

Q: Are all substitute parts 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 1SMA5949 footprint.

Q: Do all substitute parts meet the same compliance requirements? A: Yes. All substitute parts listed are ROHS3 compliant, REACH unaffected, and carry MSL 1 (Unlimited) moisture sensitivity rating, matching the original part's compliance profile.

Q: What is the difference between DO-214AC and SMAJ package designations? A: Both designations refer to the same physical package form factor. DO-214AC is the JEDEC standard designation, while SMAJ is a manufacturer-specific designation for the same package. Parts specified with either designation are mechanically and electrically compatible.

Q: Can I use a substitute part with higher impedance than the original? A: Higher impedance may affect circuit performance in voltage regulation applications. SML4764A-E3/61 specifies 350 Ohms maximum impedance compared to the original 250 Ohms. Verify circuit requirements before substitution.

Q: What does the reverse leakage current specification indicate? A: Reverse leakage current (measured at 76 V in this case) indicates the small current flowing through the Zener diode when reverse-biased below the Zener voltage. Lower leakage current generally indicates better device quality. Substitute parts show leakage values ranging from 500 nA to 5 µA, all within acceptable ranges for this device category.