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Taiwan Semiconductor Corporation 1SMB5951H
- Part No.:
- 1SMB5951H
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- Single Zener Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
1SMB5951H.pdf
- Description:
- DIODE ZENER 120V 3W DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:6,362
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Product details
Overview
1SMB5951H from Taiwan Semiconductor is a surface-mount silicon Zener diode with nominal zener voltage 120 V, 3 W total power dissipation, and DO-214AA (SMB) package. It provides precise voltage regulation and reference functions in automotive and industrial power supply circuits requiring AEC-Q101 qualification and low-inductance performance.
For engineers reviewing the 1SMB5951H datasheet, 1SMB5951H pinout, 1SMB5951H application, or 1SMB5951H equivalent, key selection criteria include its 120 V ±5% zener tolerance, 3.1 mA test current, 4500 Ω dynamic impedance at IZK, 91.2 mA maximum DC zener current, and junction temperature range of –55°C to +150°C.
Technical Context
The 1SMB5951H operates as a single-die, glass-passivated Zener diode optimized for stable voltage reference and overvoltage protection in DC power rails. Its electrical behavior is defined by a nominal zener voltage of 120 V at 3.1 mA test current, with dynamic impedance of 4500 Ω at knee current and leakage current ≤0.25 μA at 91.2 V reverse bias.
Thermally, it delivers 3 W power dissipation at lead temperature TL = 75°C (derated at 40 mW/°C above), and 550 mW at ambient TA = 25°C (derated at 4.4 mW/°C above). Junction-to-lead thermal resistance is 25°C/W, supporting reliable operation under sustained load in compact PCB layouts.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 114.0–126.0 V at IZT = 3.1 mA - defines stable regulation window for 120 V nominal rail |
| Total Power Dissipation (PTOT) | 3 W at TL = 75°C - supports continuous operation on thermally anchored pads |
| Zener Impedance (ZZK) | 4500 Ω at IZK - indicates high-impedance knee region suitable for reference, not low-noise regulation |
| Maximum DC Zener Current (IZM) | 12 mA - sets upper limit for sustained current without thermal runaway |
| Junction Temperature Range (TJ) | –55°C to +150°C - enables use in under-hood automotive and industrial environments |
| Package | DO-214AA (SMB) - surface-mount footprint compatible with automated placement and IPC-7351B standard |
| AEC-Q101 Qualified | Yes - validated for automotive-grade reliability including temperature cycling and HTRB |
Pinout & Package
DO-214AA (SMB) package: molded plastic case with matte tin-plated leads, cathode indicated by band, weight ≈0.100 g. Compliant with UL 94V-0 flammability and JESD201 Class 2 whisker resistance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / low-side connection | Connected to lower-potential node in reverse-biased Zener configuration |
| Cathode | Zener breakdown terminal / high-side connection | Marked by band; connected to higher-potential rail for voltage clamping or reference |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive electronics per stress test requirements including HTGB, HTRB, and temperature cycling |
| Glass passivated junction | Enhances long-term stability and reduces parameter drift under thermal and humidity stress |
| Low inductance construction | Minimizes voltage overshoot during transient suppression, critical for fast-rising ESD/surge events |
| Moisture sensitivity level 1 | Enables unlimited floor life before reflow; no baking required prior to assembly |
| Halogen-free & RoHS compliant | Meets IEC 61249-2-21 and EU Directive 2011/65/EU for environmentally restricted substances |
Applications
| Automotive Power Rail Protection | Industrial Sensor Reference |
|---|---|
Use Scenario: Clamping transients on 12 V and 24 V battery-fed ECUs exposed to load dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Standalone voltage clamp placed across input rail to divert surge energy to ground. Use Value: With 120 V nominal zener voltage and 3 W rating, 1SMB5951H absorbs up to 100 A peak surge (per Fig.10) without failure when properly heatsinked. | Use Scenario: Providing stable reference voltage for analog front-end circuits in programmable logic controllers (PLCs). IC Role / Device Role / Timing Role: Precision voltage reference source for ADC biasing and comparator thresholds. Use Value: 5% tolerance and low TC drift (Fig.3) ensure <±0.5% reference accuracy over –40°C to +85°C operating range. |
| DC-DC Converter Feedback | Overvoltage Detection Circuit |
Use Scenario: Secondary-side voltage sensing in isolated flyback converters where optocoupler feedback requires accurate zener reference. IC Role / Device Role / Timing Role: Zener-based shunt reference in TL431-like topology for output voltage regulation. Use Value: 120 V rating allows direct use in high-output designs (e.g., 48 V telecom supplies); 4500 Ω ZZK ensures predictable knee behavior at light loads. | Use Scenario: Triggering shutdown logic when input voltage exceeds safe threshold in medical power modules. IC Role / Device Role / Timing Role: Threshold detector via comparator input biased through resistive divider and 1SMB5951H clamp. Use Value: Sharp 120 V breakdown with <0.25 μA leakage below 91.2 V enables clean trip point definition with minimal quiescent error. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMF120A | Same DO-214AA package; 120 V nominal, but rated for 1 W only and lacks AEC-Q101 qualification | Suitable for non-automotive consumer power supplies; insufficient for sustained 3 W dissipation | Select 1SMB5951H when automotive qualification or >1 W continuous power is required |
| 1N5388B | DO-201AD package (larger); 120 V nominal, 5 W rating, but not AEC-Q101 qualified and higher thermal resistance | Better for high-power lab equipment; incompatible with dense SMT layouts due to axial footprint | Choose 1SMB5951H for space-constrained, automotive-grade SMT designs needing 3 W in SMB form factor |
Compared with SMF120A and 1N5388B, the 1SMB5951H uniquely combines AEC-Q101 compliance, 3 W SMB-rated power handling, and tight 5% zener tolerance-making it the only option meeting automotive functional safety and thermal density requirements simultaneously.
Availability
1SMB5951H is available at Aetrix Electronics and suitable for automotive ECU protection, industrial sensor reference, and DC-DC converter feedback circuits requiring stable component supply, long-lifecycle support, and AEC-Q101 traceability.
Supply support for 1SMB5951H 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, rectifiers, and protection components since 1979.
The 1SMB59xxH series was designed specifically for high-reliability automotive and industrial voltage regulation, emphasizing AEC-Q101 compliance, low moisture sensitivity, and robust thermal performance in surface-mount packages.
FAQ
What is the zener voltage tolerance of the 1SMB5951H?
The 1SMB5951H has a zener voltage tolerance of ±5%, with a nominal value of 120 V and specified range of 114.0 V to 126.0 V at 3.1 mA test current. This tolerance is confirmed in the Electrical Specifications table on page 2 of the official Taiwan Semiconductor datasheet (Version A2102), and applies across the full operating temperature range of –55°C to +150°C.
Is the 1SMB5951H suitable for automotive applications?
Yes, the 1SMB5951H is AEC-Q101 qualified, making it suitable for automotive applications including engine control units, body electronics, and ADAS power conditioning. Its glass-passivated junction, moisture sensitivity level 1, and validated performance across –55°C to +150°C junction temperature meet stringent automotive reliability requirements defined in the AEC-Q101 standard.
What is the maximum DC zener current for the 1SMB5951H?
The maximum DC zener current (IZM) for the 1SMB5951H is 12 mA, as specified in the Electrical Specifications table. This value corresponds to the current at which the device reaches its 3 W power limit at nominal zener voltage (120 V × 12 mA = 1.44 W), with thermal derating applied per the Absolute Maximum Ratings table to ensure safe operation at elevated temperatures.
Does the 1SMB5951H have a halogen-free construction?
Yes, the 1SMB5951H is halogen-free in accordance with IEC 61249-2-21, and is also RoHS compliant. These environmental specifications are explicitly stated in the FEATURES section of the Taiwan Semiconductor datasheet and verified through material declarations and third-party testing reports for the DO-214AA molding compound and lead finish.
What is the thermal resistance from junction to ambient for the 1SMB5951H?
The junction-to-ambient thermal resistance (RθJA) for the 1SMB5951H is 226°C/W, measured under standard JEDEC conditions (single-layer PCB, no copper pour). This value is provided in the THERMAL PERFORMANCE table and informs thermal design margins when estimating junction temperature rise under 3 W dissipation in real-world board layouts.
1SMB5951H 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):
- 120 V
- Tolerance:
- ±5%
- Power - Max:
- 3 W
- Impedance (Max) (Zzt):
- 360 Ohms
- Current - Reverse Leakage @ Vr:
- 1 µA @ 91.2 V
- Voltage - Forward (Vf) (Max) @ If:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AA (SMB)
1SMB5951H FAQ
1.How can I place an order for 1SMB5951H through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMB5951H 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 1SMB5951H reliable?
The price and inventory of 1SMB5951H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMB5951H is usually 5 days.
3.What payment methods are accepted for 1SMB5951H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMB5951H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMB5951H?
1SMB5951H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMB5951H 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 1SMB5951H?
For technical support, including 1SMB5951H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMB5951H requirements.
6.How does Aetrix verify that 1SMB5951H is sourced from the original manufacturer or authorized distributors?
All 1SMB5951H 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 1SMB5951H meets industry standards.
7.What is the process for return or replacement of 1SMB5951H?
All 1SMB5951H units undergo pre-shipment inspection (PSI). If there is an issue with 1SMB5951H, 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 1SMB5951H part is unused and in its original packaging.
Return procedure for 1SMB5951H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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