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Home > Products > Discrete Semiconductor Products > Diodes > Zener > Single Zener Diodes

Taiwan Semiconductor Corporation 1SMB5947

Name: 1SMB5947
Brand: Taiwan Semiconductor Corporation
SKU: 1SMB5947
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 1SMB5947

Manufacturer:: Taiwan Semiconductor Corporation

Category:: Single Zener Diodes

Package:: DO-214AA, SMB

Datasheet:: 1SMB5947.pdf

Description:: DIODE ZENER 82V 3W DO214AA

Quantity:: RFQ Add To RFQ list

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Inventory:8,797

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Product details

Overview

1SMB5947 from Taiwan Semiconductor is a 3 W surface-mount Zener diode with nominal zener voltage 82 V, test current 4.6 mA, dynamic impedance 2500 Ω at IZT, maximum DC zener current 18 mA, and DO-214AA (SMB) package. It provides precise voltage regulation in power supply feedback paths and overvoltage protection circuits.

For engineers reviewing the 1SMB5947 datasheet, 1SMB5947 pinout, 1SMB5947 application, or 1SMB5947 equivalent, key selection criteria include zener voltage tolerance (±5%), thermal resistance (R_θJA = 226 °C/W), junction temperature range (–55 to +150 °C), moisture sensitivity level (J-STD-020 Level 1), and RoHS/halogen-free compliance.

Technical Context

The 1SMB5947 operates as a single-die, glass-passivated Zener diode optimized for stable DC voltage reference and transient clamping. Its 82 V nominal breakdown voltage is specified at 4.6 mA test current, with 2500 Ω dynamic impedance ensuring predictable regulation under load variation.

Designed for surface-mount assembly on standard PCBs, it features matte tin-plated leads compliant with J-STD-002 solderability, UL 94V-0 molding compound, and cathode band polarity marking. Thermal performance is characterized by R_θJL = 25 °C/W and R_θJA = 226 °C/W under defined mounting conditions.

Key Specifications

Parameter	Value and Actual Design Meaning
V_Z (Nominal)	82 V - precise DC voltage reference point at 4.6 mA test current
I_ZT	4.6 mA - standardized test current for zener voltage measurement
Z_ZT	2500 Ω - dynamic impedance affecting regulation accuracy under varying load
P_TOT	3 W - maximum steady-state power dissipation at T_L = 75 °C
T_J Range	–55 to +150 °C - operational junction temperature limits for reliability
R_θJA	226 °C/W - thermal resistance from junction to ambient, critical for heatsinking design
Package	DO-214AA (SMB) - industry-standard SMD outline with 5.3 mm × 4.1 mm footprint

Pinout & Package

DO-214AA (SMB) package: molded plastic case with two coplanar leads, cathode indicated by a visible band. Designed for automated placement and reflow soldering on standard PCBs.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Forward conduction terminal	Connected to lower-potential node in reverse-biased regulation configuration
Cathode	Zener breakdown terminal	Marked with band; connected to higher-potential node to enable controlled avalanche conduction

Key Features

Feature	Design Value
Glass passivated junction	Enhances long-term stability and reduces parameter drift under thermal cycling
Low inductance construction	Minimizes voltage overshoot during fast transients, improving clamping fidelity
J-STD-020 Level 1 moisture sensitivity	Enables direct use without baking, reducing manufacturing overhead
RoHS and halogen-free compliance	Meets IEC 61249-2-21 and global environmental directives for end-product certification
UL 94V-0 flammability rating	Ensures flame-retardant behavior in safety-critical power applications

Applications

Switching Mode Power Supply (SMPS)	On-board DC/DC Converter
Use Scenario: Voltage feedback loop in isolated flyback or forward converter secondary-side regulation. IC Role / Device Role / Timing Role: Zener reference for optocoupler-based feedback network. Use Value: Maintains ±5% output voltage accuracy across line/load variations using 82 V nominal breakdown at 4.6 mA.	Use Scenario: Overvoltage protection clamp on 48 V intermediate bus in telecom or industrial DC/DC modules. IC Role / Device Role / Timing Role: Transient voltage suppressor triggered above 86.1 V (V_Z max). Use Value: Limits bus voltage excursion to safe levels with 2500 Ω dynamic impedance limiting clamping current rise rate.
Lighting Application	Adapter
Use Scenario: Open-circuit protection in constant-current LED driver circuits. IC Role / Device Role / Timing Role: Fail-safe shunt regulator activated when LED string opens. Use Value: Dissipates up to 3 W continuously to prevent MOSFET or controller damage, leveraging 150 °C max junction temperature rating.	Use Scenario: Secondary-side voltage reference in AC/DC wall adapters for consumer electronics. IC Role / Device Role / Timing Role: Precision zener element in TL431-like feedback divider networks. Use Value: Provides stable 82 V reference with <0.25 μA leakage at 62.2 V (V_R), minimizing standby power loss.

Switching Mode Power Supply (SMPS)

On-board DC/DC Converter

Use Scenario: Voltage feedback loop in isolated flyback or forward converter secondary-side regulation.

IC Role / Device Role / Timing Role: Zener reference for optocoupler-based feedback network.

Use Value: Maintains ±5% output voltage accuracy across line/load variations using 82 V nominal breakdown at 4.6 mA.

Use Scenario: Overvoltage protection clamp on 48 V intermediate bus in telecom or industrial DC/DC modules.

IC Role / Device Role / Timing Role: Transient voltage suppressor triggered above 86.1 V (V_Z max).

Use Value: Limits bus voltage excursion to safe levels with 2500 Ω dynamic impedance limiting clamping current rise rate.

Lighting Application

Adapter

Use Scenario: Open-circuit protection in constant-current LED driver circuits.

IC Role / Device Role / Timing Role: Fail-safe shunt regulator activated when LED string opens.

Use Value: Dissipates up to 3 W continuously to prevent MOSFET or controller damage, leveraging 150 °C max junction temperature rating.

Use Scenario: Secondary-side voltage reference in AC/DC wall adapters for consumer electronics.

IC Role / Device Role / Timing Role: Precision zener element in TL431-like feedback divider networks.

Use Value: Provides stable 82 V reference with <0.25 μA leakage at 62.2 V (V_R), minimizing standby power loss.

Equivalent & Alternatives

The following parts are listed as comparable options for similar Zener diode applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MMBZ5255B	250 mW rating, SOT-23 package, 82 V nominal, 100 Ω Z_ZT	Lower power handling; suited for signal-level biasing, not primary regulation	Select when board space is constrained and power dissipation ≤250 mW
SMBJ82A	600 W peak pulse rating, TVS diode, unidirectional, 91.1 V V_BR, 1.5 pF capacitance	Transient suppression focus; lacks tight DC regulation tolerance	Select for surge-only protection where precise DC clamping is not required

Compared with MMBZ5255B and SMBJ82A, the 1SMB5947 uniquely balances 3 W continuous power, ±5% V_Z tolerance, and 2500 Ω dynamic impedance-making it suitable for primary feedback regulation in mid-power SMPS where both precision and robustness are required.

Availability

1SMB5947 is available at Aetrix Electronics and suitable for switching mode power supplies, on-board DC/DC converters, and lighting applications requiring stable component supply and full RoHS/halogen-free compliance.

Supply support for 1SMB5947 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Taiwan Semiconductor Corporation (TSC) is a vertically integrated semiconductor manufacturer specializing in discrete power devices, analog ICs, and ESD protection solutions for industrial and consumer markets.

The 1SMB59xx series is part of TSC's high-reliability Zener diode product line, engineered for stable voltage reference and overvoltage protection in compact, automated-assembly power systems.

FAQ

What is the nominal zener voltage and tolerance of the 1SMB5947?

The 1SMB5947 has a nominal zener voltage of 82 V with a tolerance of ±5%, corresponding to a minimum of 77.9 V and maximum of 86.1 V at 4.6 mA test current. This tolerance is confirmed in the Electrical Specifications table of the official Taiwan Semiconductor datasheet (Version M2102). The 1SMB5947 achieves this specification using a glass-passivated silicon junction for long-term stability.

What is the maximum power dissipation capability of the 1SMB5947 under standard mounting conditions?

The 1SMB5947 delivers 3 W maximum power dissipation when mounted on a copper pad measuring 5 mm × 5 mm at lead temperature (T_L) of 75 °C, with derating of 40 mW/°C above that temperature. At ambient temperature (T_A) of 25 °C, its rated dissipation is 550 mW with 4.4 mW/°C derating. These values are defined in the Absolute Maximum Ratings section for the 1SMB5947.

How does the 1SMB5947 compare to standard through-hole zener diodes in terms of thermal performance?

The 1SMB5947 exhibits R_θJA = 226 °C/W and R_θJL = 25 °C/W, enabling more efficient heat transfer than typical axial-lead zeners due to its DO-214AA (SMB) surface-mount construction and low-inductance design. This allows the 1SMB5947 to sustain higher continuous power in space-constrained layouts without external heatsinking, unlike legacy DO-41 devices which typically exceed 300 °C/W R_θJA.

Is the 1SMB5947 suitable for use in automotive-grade power supplies?

The 1SMB5947 operates across –55 to +150 °C junction temperature and meets JESD201 Class 2 whisker resistance, but it is not AEC-Q200 qualified. While used in industrial and commercial power designs, the 1SMB5947 requires additional system-level validation for automotive applications. For automotive-grade alternatives, consult TSC's AEC-Q200-certified Zener portfolio-distinct from the 1SMB5947 family.

What packaging and reel quantity is offered for the 1SMB5947?

The 1SMB5947 is supplied in DO-214AA (SMB) package on tape-and-reel format, with 3,000 units per reel. This packaging supports high-speed pick-and-place assembly and complies with J-STD-020 moisture sensitivity Level 1, eliminating the need for pre-baking prior to reflow soldering. The 1SMB5947 reel packaging is standardized across Taiwan Semiconductor's 1SMB59xx series.

1SMB5947 Specifications

Product attributes: Attribute value

Manufacturer:: Taiwan Semiconductor Corporation

Series:: -

Package/Case:: DO-214AA, SMB

Packaging:: Tape & Reel (TR)

Product Status:: Active

Voltage - Zener (Nom) (Vz):: 82 V

Tolerance:: ±5%

Power - Max:: 3 W

Impedance (Max) (Zzt):: 160 Ohms

Current - Reverse Leakage @ Vr:: 1 µA @ 62.2 V

Voltage - Forward (Vf) (Max) @ If:: -

Operating Temperature:: -55°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: DO-214AA (SMB)

1SMB5947 FAQ

1.How can I place an order for 1SMB5947 through Aetrix?

Please submit a Request for Quotation (RFQ) for 1SMB5947 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for 1SMB5947 reliable?

The price and inventory of 1SMB5947 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMB5947 is usually 5 days.

3.What payment methods are accepted for 1SMB5947?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMB5947 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 1SMB5947?

1SMB5947 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 1SMB5947 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for 1SMB5947?

For technical support, including 1SMB5947 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMB5947 requirements.

6.How does Aetrix verify that 1SMB5947 is sourced from the original manufacturer or authorized distributors?

All 1SMB5947 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that 1SMB5947 meets industry standards.

7.What is the process for return or replacement of 1SMB5947?

All 1SMB5947 units undergo pre-shipment inspection (PSI). If there is an issue with 1SMB5947, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The 1SMB5947 part is unused and in its original packaging.

Return procedure for 1SMB5947:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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