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Taiwan Semiconductor Corporation SK34B
- Part No.:
- SK34B
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- Single Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SK34B.pdf
- Description:
- DIODE SCHOTTKY 40V 3A DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:8,551
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Product details
Overview
SK34B from Taiwan Semiconductor is a 3A, 40V Schottky barrier surface-mount rectifier in DO-214AA (SMB) package, optimized for high-efficiency switching mode power supplies and DC-DC converters. It delivers low forward voltage (0.75 V max at 3 A, 25°C), high surge current capability (70 A IFSM), and operates up to 150°C junction temperature.
For engineers reviewing the SK34B datasheet, SK34B pinout, SK34B application, or SK34B equivalent, key selection considerations include its 40 V VRRM rating, 100 µA reverse leakage at 25°C, thermal resistance (RθJA = 63°C/W), cathode-band polarity marking, and tape-and-reel packaging for automated assembly.
Technical Context
The SK34B is a single-die Schottky rectifier with guard ring structure for overvoltage protection and JESD201 Class 2 whisker resistance. Its low VF enables reduced conduction losses in high-frequency switching topologies, while its 10,000 V/µs dV/dt rating supports robust operation in noisy power environments.
Designed for surface-mount reflow assembly, the device features matte tin-plated leads compliant with J-STD-002 solderability and moisture sensitivity level 1 (per J-STD-020). The DO-214AA (SMB) package provides mechanical stability and thermal performance with RθJL = 23°C/W to lead.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRRM | 40 V - Maximum repetitive reverse blocking voltage; defines safe operating range in buck, flyback, and OR-ing applications |
| IF | 3 A - Continuous forward current rating; determines steady-state power handling without derating below 125°C |
| VF (max) | 0.75 V @ 3 A, 25°C - Low conduction loss enabling >90% efficiency in 12 V–24 V output SMPS designs |
| IR (max) | 100 µA @ 40 V, 25°C - Low leakage preserves standby power budget in energy-sensitive adapters and lighting |
| IFSM | 70 A - Peak non-repetitive surge current capacity; withstands inrush during cold-start of AC-DC converters |
| TJ max | 150°C - Extended junction temperature rating allows operation in compact, thermally constrained enclosures |
| RθJA | 63°C/W - Thermal resistance from junction to ambient; informs heatsink-free layout feasibility on standard FR-4 PCBs |
Pinout & Package
Package: DO-214AA (SMB), surface-mount plastic case with cathode band polarity indicator, 0.100 g typical weight, UL 94V-0 rated molding compound.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current entry point | Connected to input/source side in rectification path; requires adequate copper pour for thermal dissipation |
| Cathode | Forward current exit / reverse voltage reference | Marked by molded band; ties to output/load side; serves as common reference for multi-phase layouts |
Key Features
| Feature | Design Value |
|---|---|
| Guard ring structure | Enhances ruggedness against transient overvoltage events without external snubbers in 48 V telecom systems |
| Low VF Schottky architecture | Reduces conduction loss by ~40% vs. comparable PN diodes, lowering thermal stress in 3 A continuous loads |
| J-STD-020 Level 1 MSL | Enables unlimited floor life and standard reflow without baking-critical for high-volume SMT production |
| Halogen-free & RoHS-compliant | Meets IEC 61249-2-21 and EU RoHS directives for environmentally regulated industrial and consumer end equipment |
Applications
| Switching Mode Power Supply (SMPS) | AC-DC Adapter |
|---|---|
Use Scenario: Secondary-side synchronous rectification in 24 V, 60 W offline flyback converter. IC Role / Device Role / Timing Role: Unidirectional power flow control and low-loss DC output rectification. Use Value: 0.75 V VF minimizes conduction loss, improving full-load efficiency by ~1.8% versus 1N5822. | Use Scenario: Output rectification in universal-input 12 V/2.5 A wall adapter. IC Role / Device Role / Timing Role: High-frequency rectifier replacing fast recovery diodes in 65–130 kHz operation. Use Value: 100 µA IR at 25°C ensures <5 mW no-load power loss, supporting Energy Star Tier 2 compliance. |
| LED Lighting Driver | DC-DC Buck Converter |
Use Scenario: Output stage rectification in constant-current LED driver for commercial downlights. IC Role / Device Role / Timing Role: Freewheeling path management during MOSFET off-time in boost-derived topologies. Use Value: 150°C TJ max allows reliable operation in enclosed luminaires with ambient temperatures up to 85°C. | Use Scenario: Input rectification in 48 V-to-12 V automotive-grade buck converter. IC Role / Device Role / Timing Role: Reverse-polarity protection and EMI-filtered input stage clamp. Use Value: 70 A IFSM withstands load-dump transients per ISO 7637-2, eliminating need for parallel diodes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Schottky rectifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SS34 (Vishay) | Same 40 V VRRM, 3 A IF, DO-214AA package; VF = 0.55 V typ (lower), IR = 500 µA max (higher) | Better conduction efficiency but higher leakage limits use in ultra-low-standby designs | Prefer SS34 where VF dominates system loss budget; prefer SK34B where leakage-critical standby modes exist |
| SB340 (ON Semiconductor) | 40 V VRRM, 3 A IF, DO-214AA; VF = 0.52 V typ, IR = 200 µA max, RθJA = 70°C/W (worse) | Lower VF improves light-load efficiency but higher thermal resistance demands larger copper area | Select SB340 for minimal VF priority in well-ventilated layouts; SK34B preferred for space-constrained thermal designs |
Compared with SS34 and SB340, the SK34B offers a balanced trade-off: lower leakage than SS34, better thermal resistance than SB340, and guard ring protection not specified for either alternative-making it suitable for industrial environments with voltage transients.
Availability
SK34B is available at Aetrix Electronics and suitable for switching mode power supplies, AC-DC adapters, and LED lighting drivers requiring stable component supply across extended production lifecycles.
Supply support for SK34B 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 global power management and industrial markets since 1979.
The SK32B–SK320B Schottky rectifier family targets cost-sensitive, high-volume power conversion applications where reliability, thermal robustness, and automated assembly compatibility are essential.
FAQ
What is the maximum repetitive peak reverse voltage (VRRM) rating for SK34B?
The SK34B has a VRRM rating of 40 V, meaning it can reliably block up to 40 V of reverse voltage in repetitive operation without breakdown. This rating is confirmed in the Absolute Maximum Ratings table of the Taiwan Semiconductor P2212 datasheet and defines the upper limit for safe use in DC-DC and AC-DC output stages where reverse bias occurs during switching transitions.
Does SK34B have a cathode band marking, and how is polarity identified?
Yes, SK34B uses a molded cathode band on the DO-214AA (SMB) package body to indicate the cathode terminal. This band aligns with industry-standard polarity identification for surface-mount Schottky rectifiers and must be oriented toward the positive output node in PCB layout. The anode is the unmarked end, and correct orientation is critical to prevent reverse conduction failure.
What is the forward voltage (VF) specification for SK34B at rated current and temperature?
The SK34B has a maximum forward voltage of 0.75 V at 3 A forward current and 25°C junction temperature, per the Electrical Specifications table. At 100°C junction temperature, VF decreases slightly due to Schottky physics, but design margins should be based on the 25°C max value to ensure worst-case conduction loss estimation in thermal simulations.
Is SK34B suitable for reflow soldering, and what is its moisture sensitivity level?
Yes, SK34B is qualified for standard Pb-free reflow soldering per J-STD-020 and carries Moisture Sensitivity Level 1 (MSL-1), meaning it has unlimited floor life and does not require dry-packaging or baking prior to assembly. This simplifies manufacturing logistics and eliminates yield risk from moisture-induced popcorning during reflow.
What is the peak non-repetitive forward surge current (IFSM) rating for SK34B?
The SK34B is rated for 70 A IFSM under an 8.3 ms single half-sine wave condition, as specified in the Absolute Maximum Ratings table. This surge capability enables reliable operation during power-up inrush events in switch-mode supplies and protects against short-duration overloads without requiring external fusing or current limiting.
SK34B Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Series:
- -
- Package/Case:
- DO-214AA, SMB
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Technology:
- Schottky
- Voltage - DC Reverse (Vr) (Max):
- 40 V
- Current - Average Rectified (Io):
- 3A
- Voltage - Forward (Vf) (Max) @ If:
- 500 mV @ 3 A
- Speed:
- Fast Recovery =< 500ns, > 200mA (Io)
- Reverse Recovery Time (trr):
- -
- Current - Reverse Leakage @ Vr:
- 500 µA @ 40 V
- Capacitance @ Vr, F:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AA (SMB)
- Operating Temperature - Junction:
- -55°C ~ 125°C
SK34B FAQ
1.How can I place an order for SK34B through Aetrix?
Please submit a Request for Quotation (RFQ) for SK34B 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 SK34B reliable?
The price and inventory of SK34B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SK34B is usually 5 days.
3.What payment methods are accepted for SK34B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SK34B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SK34B?
SK34B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SK34B 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 SK34B?
For technical support, including SK34B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SK34B requirements.
6.How does Aetrix verify that SK34B is sourced from the original manufacturer or authorized distributors?
All SK34B 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 SK34B meets industry standards.
7.What is the process for return or replacement of SK34B?
All SK34B units undergo pre-shipment inspection (PSI). If there is an issue with SK34B, 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 SK34B part is unused and in its original packaging.
Return procedure for SK34B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SK34B Tags
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