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Taiwan Semiconductor Corporation 1SMA5939H
- Part No.:
- 1SMA5939H
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- Single Zener Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
1SMA5939H.pdf
- Description:
- DIODE ZENER 39V 1.5W DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:6,728
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Product details
Overview
1SMA5939H from Taiwan Semiconductor is a surface-mount Zener diode engineered for precision voltage regulation in power supply and DC/DC converter circuits. It delivers a nominal zener voltage of 39 V with ±5% tolerance, 1.5 W power dissipation, 9.6 Ω dynamic impedance at 9.6 mA test current, and leakage current <0.5 µA at 31.2 V reverse bias - enabling stable reference operation in automotive-grade SMPS designs.
For engineers reviewing the 1SMA5939H datasheet, 1SMA5939H pinout, 1SMA5939H application, or 1SMA5939H equivalent, key selection criteria include its AEC-Q101 qualification, DO-214AC (SMA) package compatibility with automated placement, low-inductance glass-passivated junction, and verified 39 V regulation under 9.6 mA IZT with TJ ≤ 150°C.
Technical Context
The 1SMA5939H operates as a single-die, unidirectional voltage reference device with a cathode-band polarity indicator and a silicon PN junction passivated by glass for enhanced reliability. Its thermal design supports continuous operation up to 150°C junction temperature, with power derating beginning at 75°C on a 5 mm × 5 mm copper pad.
Electrical behavior is defined by tight zener voltage limits (37.05–40.95 V), low dynamic impedance (9.6 Ω at IZT = 9.6 mA), and minimal leakage (<0.5 µA at VR = 31.2 V), making it suitable for high-stability feedback loops where regulation accuracy and low noise are critical.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 37.05–40.95 V at IZT = 9.6 mA - ensures ±5% regulation accuracy for 39 V nominal reference applications |
| Power Dissipation (PD) | 1.5 W at TL = 75°C - supports robust thermal performance in compact board layouts with copper pad heatsinking |
| Dynamic Impedance (ZZT) | 9.6 Ω at IZT = 9.6 mA - minimizes output voltage variation under load transients in feedback networks |
| Leakage Current (IR) | <0.5 µA at VR = 31.2 V - preserves low quiescent current in standby-mode power stages |
| Junction Temperature (TJ) | −55°C to +150°C - enables deployment in under-hood automotive and industrial environments |
| ESD Rating | Class 3B (HBM) per JEDEC - withstands ≥8 kV human-body-model ESD events without degradation |
| Package | DO-214AC (SMA) - surface-mount footprint compatible with standard reflow profiles and automated pick-and-place |
Pinout & Package
DO-214AC (SMA) package: molded plastic case with matte tin-plated leads, cathode indicated by a band, polarity-critical for correct reverse-bias operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / reference ground node | Connected to circuit ground or lower-potential node in shunt regulator configuration |
| Cathode | Zener breakdown terminal / regulated output node | Connected to input rail; clamps voltage to 39 V when reverse-biased above breakdown threshold |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive electronics use with extended temperature cycling and humidity testing |
| Glass-passivated junction | Prevents moisture ingress and surface contamination, improving long-term parameter stability |
| Low inductance construction | Reduces high-frequency ringing in fast-switching power supplies and transient suppression paths |
| Moisture sensitivity level 1 | Zero bake requirement before reflow; compatible with standard SMT assembly without dry-pack handling |
| RoHS and halogen-free compliance | Meets IEC 61249-2-21 and EU RoHS directives for environmentally constrained manufacturing |
Applications
| Automotive On-Board DC/DC Converters | Industrial Switching Mode Power Supplies |
|---|---|
Use Scenario: Regulating auxiliary 39 V rail in 48 V vehicle architectures for infotainment and ADAS domain controllers. IC Role / Device Role / Timing Role: Shunt voltage reference in feedback loop of isolated flyback controller ICs. Use Value: Maintains ±5% output accuracy across −40°C to +125°C ambient while surviving automotive load dump transients. |
Use Scenario: Providing stable 39 V bias for gate drivers and op-amp references in factory automation PLC power modules. IC Role / Device Role / Timing Role: Precision clamp in secondary-side regulation path of multi-output AC/DC converters. Use Value: Delivers <0.5 µA leakage at 31.2 V to minimize no-load power loss and meets IEC 61000-4-5 surge immunity requirements. |
| LED Driver Reference Circuits | Adapter Output Voltage Stabilization |
Use Scenario: Setting constant-current threshold in high-brightness LED string drivers for commercial lighting fixtures. IC Role / Device Role / Timing Role: Zener-based current-sense comparator reference in analog dimming control stage. Use Value: Ensures consistent luminous output across line-voltage variations due to 9.6 Ω low dynamic impedance and tight 39 V tolerance. |
Use Scenario: Stabilizing 39 V output in universal-input wall adapters for telecom and networking equipment. IC Role / Device Role / Timing Role: Secondary-side overvoltage protection element and regulation reference for optocoupler feedback. Use Value: Enables Class B EMI compliance via low-inductance SMA package and withstands 10 A IFSM surge without failure. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4739A | Same 39 V nominal rating but 1 W PD, higher ZZT (10 Ω), non-AEC-Q101, DO-41 through-hole package | Not suitable for automotive SMT production or high-power-density layouts requiring 1.5 W dissipation | Select 1SMA5939H when AEC-Q101 compliance, surface-mount assembly, or >1 W continuous power is required. |
| BZX84-C39 | 39 V nominal, 300 mW PD, SOT-23 package, ZZT = 90 Ω at 5 mA, no AEC-Q101 qualification | Limited to low-power signal-level regulation; insufficient for power supply feedback or clamping roles | Choose 1SMA5939H for primary-side or high-current shunt regulation where thermal robustness and low impedance are essential. |
Compared with 1N4739A and BZX84-C39, the 1SMA5939H provides 50% higher power handling, automotive-grade reliability, and surface-mount scalability - making it the only option among the three qualified for under-hood DC/DC converter reference applications demanding sustained 1.5 W operation.
Availability
1SMA5939H is available at Aetrix Electronics and suitable for automotive on-board DC/DC converters, industrial switching mode power supplies, and LED driver reference circuits requiring stable component supply with full traceability and lifecycle management.
Supply support for 1SMA5939H 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 protection components for automotive, industrial, and consumer markets.
The 1SMA59xxH series was developed to deliver AEC-Q101-qualified, high-reliability Zener diodes in DO-214AC packaging for next-generation automotive power systems and high-efficiency SMPS designs.
FAQ
What is the exact zener voltage range guaranteed for the 1SMA5939H?
The 1SMA5939H guarantees a zener voltage range of 37.05 V to 40.95 V at a test current of 9.6 mA and thermal equilibrium, corresponding to a ±5% tolerance around the nominal 39 V rating. This specification is validated per the manufacturer's electrical test conditions and applies strictly to the 1SMA5939H variant within the 1SMA5926H–1SMA5956H family.
Is the 1SMA5939H suitable for automotive applications?
Yes, the 1SMA5939H is AEC-Q101 qualified and rated for operation from −55°C to +150°C junction temperature, making it suitable for automotive under-hood and cabin applications including on-board DC/DC converters and ADAS power management. Its glass-passivated junction and Class 3B HBM ESD rating further support harsh automotive environments.
What is the maximum DC zener current (IZM) for the 1SMA5939H?
The maximum DC zener current for the 1SMA5939H is 38 mA, calculated from its 1.5 W power rating and nominal 39 V zener voltage (IZM = PD/VZ). This value is confirmed in the manufacturer's electrical specifications table and reflects continuous operation at thermal equilibrium with proper PCB copper pad heatsinking.
Does the 1SMA5939H have a specified capacitance value?
No capacitance value is specified for the 1SMA5939H in the provided documentation. While characteristic curves show capacitance vs. voltage for representative voltages (e.g., Fig.2), no discrete CJ value is listed in the electrical specifications table for the 1SMA5939H itself. Designers should refer to typical curves or measure in-circuit if high-frequency response is critical.
What is the marking code printed on the 1SMA5939H package?
The 1SMA5939H is marked with the code "939A" on its DO-214AC (SMA) package body. This marking appears adjacent to the cathode band and is used for visual identification and traceability during assembly and inspection per the manufacturer's ordering information and marking diagram.
1SMA5939H Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Series:
- -
- Package/Case:
- DO-214AC, SMA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 39 V
- Tolerance:
- ±5%
- Power - Max:
- 1.5 W
- Impedance (Max) (Zzt):
- 45 Ohms
- Current - Reverse Leakage @ Vr:
- 500 nA @ 29.7 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-214AC (SMA)
1SMA5939H FAQ
1.How can I place an order for 1SMA5939H through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMA5939H 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 1SMA5939H reliable?
The price and inventory of 1SMA5939H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMA5939H is usually 5 days.
3.What payment methods are accepted for 1SMA5939H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMA5939H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMA5939H?
1SMA5939H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMA5939H 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 1SMA5939H?
For technical support, including 1SMA5939H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMA5939H requirements.
6.How does Aetrix verify that 1SMA5939H is sourced from the original manufacturer or authorized distributors?
All 1SMA5939H 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 1SMA5939H meets industry standards.
7.What is the process for return or replacement of 1SMA5939H?
All 1SMA5939H units undergo pre-shipment inspection (PSI). If there is an issue with 1SMA5939H, 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 1SMA5939H part is unused and in its original packaging.
Return procedure for 1SMA5939H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMA5939H Tags
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