My Inquiry
My Account
Taiwan Semiconductor Corporation SK33B
- Part No.:
- SK33B
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- Single Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SK33B.pdf
- Description:
- DIODE SCHOTTKY 30V 3A DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:7,735
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SK33B from Taiwan Semiconductor is a 3A, 30V Schottky barrier surface-mount rectifier in DO-214AA (SMB) package, designed for high-efficiency DC/DC conversion with low forward voltage (0.75 V max at 3 A, 25°C), high surge current capability (70 A), and junction temperature up to +150°C. It serves as a primary output rectifier in compact AC/DC adapters and offline SMPS.
For engineers reviewing the SK33B datasheet, SK33B pinout, SK33B application, or SK33B equivalent, key selection criteria include its 30 V repetitive peak reverse voltage, 100 µA max reverse leakage at 25°C, 23°C/W junction-to-lead thermal resistance, and compatibility with automated SMT placement per J-STD-020 Level 1 moisture sensitivity.
Technical Context
The SK33B employs a single-die Schottky structure optimized for low conduction loss in medium-voltage switching applications. Its guard ring design enhances overvoltage ruggedness, while the matte tin-plated leads ensure reliable solderability per J-STD-002.
With a critical rate of rise of off-state voltage (dV/dt) rated at 10,000 V/µs and thermal resistance RθJA of 63°C/W, the SK33B supports stable operation under transient load conditions and moderate PCB copper area without forced airflow.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRRM | 30 V - Maximum non-repetitive reverse blocking voltage; defines safe operating limit in flyback or buck output stages |
| IF | 3 A continuous - Rated average forward current at case temperature ≤ 75°C; supports sustained 12–24 V output rails |
| VF (max) | 0.75 V at 3 A, 25°C - Low conduction loss enables >92% efficiency in 5–24 V secondary-side rectification |
| IR (max) | 100 µA at 30 V, 25°C - Minimal leakage preserves light-load regulation and standby power compliance |
| IFSM | 70 A (8.3 ms half-sine) - Withstands inrush and short-circuit transients in unregulated converters |
| TJ (max) | +150°C - Enables operation in sealed enclosures or high-ambient industrial environments |
| RθJL | 23°C/W - Efficient heat transfer to PCB copper; allows thermal relief pad design without heatsink |
Pinout & Package
DO-214AA (SMB) surface-mount package with cathode-indicated band; 0.100 g mass; UL 94V-0 molded compound; polarity marked by visible cathode band on body.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current input | Connected to transformer secondary or switch node; requires low-inductance layout for EMI control |
| Cathode | Forward current output / reverse voltage reference | Connected to output capacitor and load; cathode band orientation must match PCB silkscreen |
Key Features
| Feature | Design Value |
|---|---|
| Guard ring protection | Prevents edge breakdown under voltage transients, improving reliability in noisy SMPS environments |
| Moisture sensitivity level 1 | No baking required before reflow; compatible with standard SMT assembly lines without dry-pack handling |
| Halogen-free construction | Meets IEC 61249-2-21; supports RoHS-compliant and environmentally regulated end equipment |
| High surge current rating | 70 A IFSM enables robustness against output capacitor inrush and fault currents without derating |
Applications
| AC/DC Adapters | Industrial SMPS |
|---|---|
Use Scenario: 12 V/2.5 A wall adapter for networking equipment with tight no-load power requirements. IC Role / Device Role / Timing Role: Output rectifier replacing conventional PN diodes to reduce conduction loss and improve efficiency. Use Value: 0.75 V VF lowers dissipation by ~0.4 W vs. 1.1 V Si diode, enabling smaller heatsink and meeting DOE VI/ERP Tier 2 standards. | Use Scenario: 24 V, 3 A auxiliary supply in PLC backplane with ambient temperature up to 70°C. IC Role / Device Role / Timing Role: Primary secondary-side rectifier in isolated flyback converter with synchronous control disabled. Use Value: +150°C TJ rating and 23°C/W RθJL allow full 3 A load at 70°C ambient without thermal throttling. |
| LED Drivers | DC/DC Converters |
Use Scenario: Constant-current LED driver for commercial downlights using quasi-resonant flyback topology. IC Role / Device Role / Timing Role: Secondary-side rectifier handling pulsed 3 A output with high dV/dt stress during MOSFET turn-off. Use Value: 10,000 V/µs dV/dt rating prevents false turn-on and ensures stable operation with fast-switching controllers. | Use Scenario: 5 V/3 A buck-derived point-of-load supply in telecom baseband unit. IC Role / Device Role / Timing Role: Freewheeling diode in non-synchronous buck regulator operating at 300 kHz. Use Value: Low 0.75 V VF minimizes duty-cycle-dependent voltage drop, maintaining tight output regulation across load range. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Schottky rectifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SS33 (Vishay) | Same 30 V VRRM, 3 A IF, but VF = 0.52 V typ (25°C); RθJA = 70°C/W | Better conduction loss at light loads; higher thermal resistance limits high-ambient use | Prefer SS33 where ultra-low VF dominates over thermal margin |
| SB330 (ON Semiconductor) | 30 V VRRM, 3 A IF, VF = 0.52 V typ; IR = 200 µA max at 25°C (vs. SK33B's 100 µA) | Higher leakage may impact standby power in energy-sensitive designs | Choose SB330 when lower VF justifies slightly higher IR in cost-sensitive consumer adapters |
Compared with SS33 and SB330, the SK33B offers tighter reverse leakage (100 µA) and superior thermal performance (23°C/W RθJL), making it preferred for industrial-grade supplies requiring long-term reliability at elevated temperatures.
Availability
SK33B is available at Aetrix Electronics and suitable for AC/DC adapters, industrial SMPS, and LED drivers requiring stable component supply, consistent parametric performance, and long-term manufacturing continuity.
Supply support for SK33B 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, specializing in power rectifiers, TVS devices, and bipolar transistors.
The SK32B–SK320B family was developed to deliver high-reliability, low-VF Schottky rectifiers for cost-sensitive yet thermally demanding power conversion applications across consumer, industrial, and lighting markets.
FAQ
What is the maximum junction temperature rating for SK33B?
The SK33B has a maximum junction temperature (TJ) rating of +150°C, verified per absolute maximum ratings table in the official Taiwan Semiconductor datasheet P2212. This allows uninterrupted operation in enclosed industrial power supplies where case temperatures exceed 85°C. The SK33B maintains specified electrical parameters up to this limit when thermal design respects RθJL = 23°C/W and RθJA = 63°C/W.
Does SK33B have a halogen-free construction?
Yes, the SK33B is halogen-free in accordance with IEC 61249-2-21, as explicitly stated in the "Features" section of the Taiwan Semiconductor datasheet P2212. This compliance supports environmental regulations including JEDEC J-STD-609 and enables use in green-certified end equipment such as ENERGY STAR–qualified adapters and EU Ecodesign-compliant lighting systems.
What is the reverse leakage current of SK33B at 100°C?
At junction temperature of 100°C and rated reverse voltage (30 V), the SK33B exhibits a maximum reverse leakage current (IR) of 5 mA, per the Electrical Specifications table in datasheet P2212. This value is confirmed under 30 ms pulse test conditions and reflects real-world behavior in high-temperature SMPS designs where thermal runaway risk must be evaluated.
Is SK33B suitable for automated SMT placement?
Yes, the SK33B is explicitly designed for automated placement, as noted in the "Features" section of the Taiwan Semiconductor datasheet. Its DO-214AA (SMB) package meets J-STD-020 moisture sensitivity level 1, eliminating bake requirements, and its matte tin-plated leads comply with J-STD-002 for solderability-ensuring high first-pass yield in high-volume reflow lines.
What does the marking code 'SK33B' indicate on the device body?
The marking code 'SK33B' laser-etched on the SK33B device body directly identifies the part as the 30 V variant within the SK3xB Schottky rectifier series, per the Ordering Information section of datasheet P2212. The 'B' suffix denotes the SMB package variant, distinguishing it from through-hole equivalents, and the cathode band provides unambiguous polarity orientation during placement.
SK33B 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):
- 30 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 @ 30 V
- Capacitance @ Vr, F:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AA (SMB)
- Operating Temperature - Junction:
- -55°C ~ 125°C
SK33B FAQ
1.How can I place an order for SK33B through Aetrix?
Please submit a Request for Quotation (RFQ) for SK33B 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 SK33B reliable?
The price and inventory of SK33B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SK33B is usually 5 days.
3.What payment methods are accepted for SK33B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SK33B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SK33B?
SK33B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SK33B 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 SK33B?
For technical support, including SK33B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SK33B requirements.
6.How does Aetrix verify that SK33B is sourced from the original manufacturer or authorized distributors?
All SK33B 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 SK33B meets industry standards.
7.What is the process for return or replacement of SK33B?
All SK33B units undergo pre-shipment inspection (PSI). If there is an issue with SK33B, 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 SK33B part is unused and in its original packaging.
Return procedure for SK33B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SK33B Tags
-
1N4448X-TP
Micro Commercial Co
-
1N4148WX-TP
Micro Commercial Co
-
1N4148TR
onsemi
-
MMSD4148T1G
onsemi
-
MMBD914LT3G
onsemi
-
BAS16HT1G
onsemi
-
1N914BWT
onsemi
-
BAS21LT1G
onsemi
-
LL4148
onsemi
-
BAS16LT1G
onsemi
-
MMSD914T1G
onsemi
-
BAV21W-7-F
Diodes Incorporated
Tech Hub
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
