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Diodes Incorporated 1SMB5943B-13
- Part No.:
- 1SMB5943B-13
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Zener Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
1SMB5943B-13.pdf
- Description:
- DIODE ZENER 56V 3W SMB
- Quantity:
- Payment:
- Shipping:
Inventory:93
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Product details
Overview
1SMB5943B-13 from Diodes Incorporated is a 3.0W surface-mount power Zener diode with a nominal zener voltage of 56V (±5%), 6.7Ω dynamic impedance at 86mA test current, and 0.25µA maximum reverse leakage at 42.6V. It features ESD rating >16kV (HBM), RoHS-compliant lead-free finish, and SMB package for high-reliability voltage regulation in DC power rails.
For engineers reviewing the 1SMB5943B-13 datasheet, 1SMB5943B-13 pinout, 1SMB5943B-13 application, or 1SMB5943B-13 equivalent, key selection criteria include zener voltage tolerance, power derating above +25°C, thermal resistance (RθJA = 226°C/W), and compliance with Class 3 ESD and halogen-free "Green" requirements.
Technical Context
This discrete Zener diode operates in reverse breakdown to maintain stable reference voltage under varying load and temperature conditions. Its 56V nominal zener voltage is specified at IZT = 86mA, with dynamic impedance measured at 60Hz AC signal (IZ(AC) = 0.1 × IZ(DC)).
Thermal performance is defined for FR-4 PCB mounting per AP02001 pad layout: power dissipation drops linearly from 550mW at +25°C to 0W at +160°C (derating slope 4.4mW/°C), while junction-to-terminal resistance is 25°C/W for heatsink-assisted operation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 56V nominal, ±5% tolerance - ensures precise voltage clamping within 53.2–58.8V range at 86mA |
| Power Dissipation (PD) | 550mW @ TA = +25°C - defines maximum continuous DC power on standard PCB without forced cooling |
| Zener Impedance (ZZT) | 6.7Ω @ IZT = 86mA - low dynamic resistance enables tight regulation under transient load changes |
| Reverse Leakage (IR) | 0.25µA @ VR = 42.6V - minimal standby current preserves efficiency in low-power bias networks |
| ESD Rating | Class 3 (>16kV HBM) - withstands high-energy electrostatic discharge without parameter shift or failure |
| Operating Temperature | −65°C to +150°C - supports industrial and automotive under-hood environments |
| Package | SMB (DO-214AA) - standardized surface-mount outline with cathode band polarity marking |
Pinout & Package
SMB package: molded plastic case (UL 94V-0), copper alloy leadframe with matte tin plating, cathode band marking, weight ≈ 0.096g. Moisture sensitivity level 1 (J-STD-020).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener cathode reference node | Connected to lower-potential side of regulated rail; forms reference ground for shunt regulation |
| Cathode | Zener breakdown terminal / voltage clamp input | Connected to higher-potential supply node; conducts when VIN exceeds 56V to divert excess current |
Key Features
| Feature | Design Value |
|---|---|
| 3.0W peak pulse power capability | Supports transient overvoltage suppression up to 10× rated DC power (per Figure 10, 10ms pulse) |
| Halogen- and antimony-free "Green" construction | Meets <900ppm Br, <900ppm Cl, <1000ppm Sb - satisfies strict environmental compliance for export markets |
| Automated assembly compatibility | SMB footprint aligns with IPC-7351B standards - enables high-yield pick-and-place and reflow processing |
| Low thermal resistance (RθJT = 25°C/W) | Enables direct thermal coupling to copper pour or heatsink tab for sustained 3W operation |
Applications
| Industrial Power Supply Protection | Automotive Body Control Module |
|---|---|
Use Scenario: Clamp 12V/24V rail surges during load dump or alternator transients in programmable logic controllers. IC Role / Device Role / Timing Role: Shunt regulator protecting downstream LDOs and microcontrollers from >60V spikes. Use Value: 56V zener voltage provides 10V margin above 42.6V worst-case load-dump peak, ensuring reliable clamping before IC damage. | Use Scenario: Stabilize reference voltage for CAN transceiver biasing in door module ECUs. IC Role / Device Role / Timing Role: Precision voltage reference for isolated CAN bus power domain. Use Value: ±5% VZ tolerance and <0.25µA leakage enable stable 5V LDO input across −40°C to +125°C ambient. |
| Telecom DC-DC Converter Feedback | Medical Diagnostic Equipment Biasing |
Use Scenario: Provide accurate feedback reference for isolated flyback converters powering FPGA I/O banks. IC Role / Device Role / Timing Role: Secondary-side voltage reference in optocoupler-coupled feedback loop. Use Value: 6.7Ω ZZT minimizes regulation error under dynamic load steps, maintaining <±1% output accuracy. | Use Scenario: Establish stable bias for photodiode amplifier stages in portable ultrasound front-ends. IC Role / Device Role / Timing Role: Low-noise voltage reference for analog signal chain conditioning. Use Value: Class 3 ESD rating prevents latch-up during handling, and 150°C max TJ supports sealed enclosure thermal profiles. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N5943B | Same 56V VZ, but DO-41 through-hole package; RθJA = 500°C/W vs. 226°C/W | Not suitable for high-density SMT layouts; requires manual insertion or wave soldering | Select only if legacy through-hole design or thermal constraints permit larger board area |
| BZX85C56 | 56V VZ, ±5%, but 1.3W PD; ZZT = 40Ω @ 5mA - higher impedance limits regulation precision | Limited to low-current references (<10mA); unsuitable for >100mA surge clamping | Choose only for cost-sensitive, low-power bias networks where 56V tolerance is primary requirement |
Compared with 1N5943B and BZX85C56, the 1SMB5943B-13 delivers superior thermal performance (226°C/W vs. 500°C/W), higher surge capability (3.0W vs. 1.3W), and tighter dynamic impedance (6.7Ω vs. 40Ω), making it optimal for space-constrained, high-reliability SMT power regulation.
Availability
1SMB5943B-13 is available at Aetrix Electronics and suitable for industrial power supply protection, automotive body control modules, and telecom DC-DC converter feedback requiring stable component supply and full traceability.
Supply support for 1SMB5943B-13 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design centers across Asia and manufacturing in China, Taiwan, and Malaysia.
This device belongs to the SMB-series surface-mount Zener diode product line, engineered specifically for high-power, high-reliability voltage regulation and transient suppression in compact SMT designs.
FAQ
What is the maximum continuous DC current the 1SMB5943B-13 can handle at room temperature?
The device supports a maximum zener current of 86mA at its specified test condition (IZT), corresponding to 550mW power dissipation at +25°C ambient. At this current, VZ remains within 53.2–58.8V, and thermal rise stays within safe junction limits when mounted per AP02001 pad layout.
Does the 1SMB5943B-13 meet automotive AEC-Q200 stress testing requirements?
No - while rated for −65°C to +150°C operating temperature and Class 3 ESD, the 1SMB5943B-13 is not AEC-Q200 qualified. For automotive-grade applications, Diodes Incorporated offers the AZ series (e.g., AZ56B) with full AEC-Q200 certification and extended reliability testing.
Can this Zener diode be used in parallel for higher power handling?
Not recommended - mismatched zener voltages between parallel units cause current hogging, leading to thermal runaway. For >3W requirements, use a single higher-rated device (e.g., SMAZ56A) or implement active regulation with a transistor-based shunt circuit.
What is the typical capacitance of the 1SMB5943B-13 at 0V bias?
Per Figure 7 in DS32125 Rev. 8-2, total capacitance is approximately 120pF at VR = 0V and f = 1MHz. This value decreases with increasing reverse bias and must be accounted for in high-frequency filtering or RF-coupled circuits.
1SMB5943B-13 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- DO-214AA, SMB
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 56 V
- Tolerance:
- ±5%
- Power - Max:
- 3 W
- Impedance (Max) (Zzt):
- 86 Ohms
- Current - Reverse Leakage @ Vr:
- 1 µA @ 42.6 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.5 V @ 200 mA
- Operating Temperature:
- -65°C ~ 150°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMB
1SMB5943B-13 FAQ
1.How can I place an order for 1SMB5943B-13 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMB5943B-13 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 1SMB5943B-13 reliable?
The price and inventory of 1SMB5943B-13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMB5943B-13 is usually 5 days.
3.What payment methods are accepted for 1SMB5943B-13?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMB5943B-13 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMB5943B-13?
1SMB5943B-13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMB5943B-13 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 1SMB5943B-13?
For technical support, including 1SMB5943B-13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMB5943B-13 requirements.
6.How does Aetrix verify that 1SMB5943B-13 is sourced from the original manufacturer or authorized distributors?
All 1SMB5943B-13 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 1SMB5943B-13 meets industry standards.
7.What is the process for return or replacement of 1SMB5943B-13?
All 1SMB5943B-13 units undergo pre-shipment inspection (PSI). If there is an issue with 1SMB5943B-13, 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 1SMB5943B-13 part is unused and in its original packaging.
Return procedure for 1SMB5943B-13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMB5943B-13 Tags
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