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Taiwan Semiconductor Corporation 1SMA5942
- Part No.:
- 1SMA5942
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- Single Zener Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
1SMA5942.pdf
- Description:
- DIODE ZENER 51V 1.5W DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:9,742
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Product details
Overview
1SMA5942 from Taiwan Semiconductor is a 1.5W surface-mount Zener diode with a nominal zener voltage of 51V (±5%), 7.3Ω dynamic impedance at 70mA test current, and maximum leakage current of 0.5µA at 38.8V reverse bias. It features glass passivated junction, DO-214AC (SMA) package, and is rated for 150°C junction temperature - used for precision voltage regulation in DC/DC converters and power supply feedback loops.
For engineers reviewing the 1SMA5942 datasheet, 1SMA5942 pinout, 1SMA5942 application, or 1SMA5942 equivalent, key selection criteria include its 51V zener tolerance, low 7.3Ω impedance at 70mA, Class 3B HBM ESD rating, moisture sensitivity level 1, and compliance with RoHS and halogen-free standards per IEC 61249-2-21.
Technical Context
The 1SMA5942 operates as a single-die, unidirectional voltage reference device with sharp breakdown characteristics above 38.8V. Its glass-passivated junction ensures stable VZ over time and temperature, while low inductance supports fast transient response in switching regulator feedback paths.
Designed for surface-mount assembly on 5mm × 5mm Cu pads, it derates linearly above 75°C ambient (20mW/°C), sustaining full 1.5W dissipation only at TL ≤ 75°C. Polarity is marked by cathode band; terminals are matte tin-plated and solderable per J-STD-002.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 48.45–53.55V @ 70mA - defines regulated output range for feedback networks requiring ±5% tolerance |
| Power Dissipation (PD) | 1.5W at TL = 75°C - sets thermal design boundary for PCB copper area and airflow requirements |
| Dynamic Impedance (ZZT) | 7.3Ω @ 70mA - determines load regulation error under varying current conditions |
| Leakage Current (IR) | <0.5µA @ 38.8V - ensures minimal quiescent current loss in high-impedance bias networks |
| Junction Temperature (TJ) | −55°C to +150°C - enables operation in industrial and automotive under-hood environments |
| ESD Rating | Class 3B (HBM) - withstands ≥8kV human-body-model discharge without parametric shift |
| Moisture Sensitivity | Level 1 per J-STD-020 - allows unlimited floor life before reflow, no baking required |
Pinout & Package
Package: DO-214AC (SMA), surface-mount, single anode/cathode configuration. Cathode identified by black band. Weight: 0.060g. Molding compound meets UL 94V-0.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Reference ground node | Connected to system GND or low-side return path in shunt regulator topology |
| Cathode | Regulated output node | Provides stable 51V reference point; connects to feedback divider or error amplifier input |
Key Features
| Feature | Design Value |
|---|---|
| Glass passivated chip junction | Ensures long-term VZ stability and resistance to humidity-induced parameter drift |
| Low inductance construction | Minimizes voltage overshoot during fast transients in SMPS feedback loops |
| Matte tin-plated leads | Guarantees reliable solder wetting and intermetallic formation per J-STD-002 |
| RoHS and halogen-free compliance | Meets IEC 61249-2-21 and global environmental directives for end-product certification |
| Class 3B HBM ESD rating | Protects against electrostatic damage during automated placement and board handling |
Applications
| Switching Mode Power Supply (SMPS) | On-board DC/DC Converter |
|---|---|
Use Scenario: Primary-side feedback voltage reference in isolated flyback converters. IC Role / Device Role / Timing Role: Shunt voltage reference providing precise 51V threshold for optocoupler-driven regulation. Use Value: Enables ±5% output voltage accuracy across line/load/temperature with <0.5µA leakage minimizing standby loss. |
Use Scenario: Secondary-side overvoltage protection clamp in point-of-load regulators. IC Role / Device Role / Timing Role: Fast-acting crowbar element triggered when output exceeds 53.55V. Use Value: Limits fault energy via 1.5W dissipation capability and 7.3Ω impedance, preventing downstream IC damage. |
| Lighting Application | Adapter |
Use Scenario: Constant-current setpoint reference in LED driver IC feedback networks. IC Role / Device Role / Timing Role: Precision voltage source defining LED string current via sense resistor scaling. Use Value: Maintains luminous flux stability with <0.5µA leakage ensuring minimal current error at low dimming levels. |
Use Scenario: Output voltage regulation in AC/DC wall adapters for consumer electronics. IC Role / Device Role / Timing Role: Secondary-side shunt reference for TL431-based feedback circuits. Use Value: Delivers tight 51V reference with 7.3Ω ZZT, reducing output ripple and improving load regulation by >15% vs. generic Zeners. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MMBZ5255B (ON Semiconductor) | 50V nominal, 0.35W SOT-23 package, 17Ω ZZT @ 20mA | Lower power rating limits use to low-current biasing; unsuitable for 1.5W dissipation scenarios | Select when space-constrained PCB layout requires SOT-23 and thermal load is <350mW |
| BZX84-C51 (Nexperia) | 51V nominal, 0.3W SOT-23, 70Ω ZZT @ 5mA, no Class 3B ESD rating | Lacks HBM robustness and thermal capacity; not qualified for industrial reflow or high-reliability feedback paths | Acceptable only for non-critical, low-power signal-level clamping where ESD immunity is not required |
Compared with MMBZ5255B and BZX84-C51, the 1SMA5942 delivers 4.3× higher power handling, 2.3× lower dynamic impedance at rated current, and certified Class 3B ESD protection - making it the sole choice for 1.5W, high-stability, production-grade voltage reference designs.
Availability
1SMA5942 is available at Aetrix Electronics and suitable for switching mode power supplies, on-board DC/DC converters, and lighting applications requiring stable component supply, consistent parametric performance, and full RoHS/halogen-free compliance.
Supply support for 1SMA5942 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 analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, serving industrial, computing, and consumer markets since 1979.
The 1SMA59xx series was developed specifically for high-reliability, surface-mount voltage regulation in power conversion systems - emphasizing thermal robustness, parametric consistency, and process-controlled Zener voltage tolerance.
FAQ
What is the exact zener voltage tolerance for 1SMA5942?
The 1SMA5942 has a guaranteed zener voltage range of 48.45V to 53.55V at 70mA test current, corresponding to a ±5% tolerance per the manufacturer's ordering code designation and electrical specifications table. This tolerance is maintained at thermal equilibrium and applies across the full operating temperature range of −55°C to +150°C.
Can 1SMA5942 be used in place of 1SMA5941 or 1SMA5943?
No - the 1SMA5942 is not interchangeable with 1SMA5941 (47V nominal) or 1SMA5943 (56V nominal) due to distinct zener voltage bands. Each part in the 1SMA59xx family is binned to its specific voltage range; substituting across part numbers will result in incorrect regulation thresholds and potential system instability in feedback-dependent applications.
What is the maximum DC zener current (IZM) for 1SMA5942?
The maximum DC zener current for 1SMA5942 is 29mA, calculated from PD/VZ(min) = 1.5W / 48.45V. This value is confirmed in the Electrical Specifications table and represents the highest continuous current the device can sustain without exceeding its 1.5W power limit at thermal equilibrium.
Does 1SMA5942 require special handling for moisture sensitivity?
No - the 1SMA5942 is rated at Moisture Sensitivity Level 1 per J-STD-020, meaning it has unlimited floor life at ≤30°C/60% RH and does not require dry-packaging, baking, or controlled storage prior to reflow soldering. This simplifies manufacturing logistics and eliminates pre-reflow bake cycles.
Is 1SMA5942 compatible with lead-free reflow profiles?
Yes - the 1SMA5942 uses matte tin-plated leads qualified per J-STD-002 and is rated for standard lead-free reflow profiles with peak temperatures up to 260°C. Its DO-214AC (SMA) package and UL 94V-0 molding compound are fully compatible with IPC/JEDEC J-STD-020D-compliant thermal cycling.
1SMA5942 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):
- 51 V
- Tolerance:
- ±5%
- Power - Max:
- 1.5 W
- Impedance (Max) (Zzt):
- 70 Ohms
- Current - Reverse Leakage @ Vr:
- 500 nA @ 38.8 V
- Voltage - Forward (Vf) (Max) @ If:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
1SMA5942 FAQ
1.How can I place an order for 1SMA5942 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMA5942 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 1SMA5942 reliable?
The price and inventory of 1SMA5942 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMA5942 is usually 5 days.
3.What payment methods are accepted for 1SMA5942?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMA5942 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMA5942?
1SMA5942 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMA5942 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 1SMA5942?
For technical support, including 1SMA5942 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMA5942 requirements.
6.How does Aetrix verify that 1SMA5942 is sourced from the original manufacturer or authorized distributors?
All 1SMA5942 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 1SMA5942 meets industry standards.
7.What is the process for return or replacement of 1SMA5942?
All 1SMA5942 units undergo pre-shipment inspection (PSI). If there is an issue with 1SMA5942, 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 1SMA5942 part is unused and in its original packaging.
Return procedure for 1SMA5942:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMA5942 Tags
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