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Diodes Incorporated SK33-7
- Part No.:
- SK33-7
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SK33-7.pdf
- Description:
- DIODE SCHOTTKY 30V 3A SMC
- Quantity:
- Payment:
- Shipping:
Inventory:5,715
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Product details
Overview
SK33-7 from Diodes Incorporated is a surface-mount Schottky barrier rectifier rated for 30 V maximum recurrent peak reverse voltage, 3.0 A average forward rectified current, and 0.75 V maximum forward voltage at 3.0 A, used in DC/DC converter output stages and low-voltage AC-DC power supplies.
For engineers reviewing the SK33-7 datasheet, SK33-7 pinout, SK33-7 application, or SK33-7 equivalent, key selection criteria include VF vs. IR trade-off at 100°C, thermal resistance (RJA = 60 °C/W), surge rating (100 A @ 8.3 ms), and SMC package compatibility with high-density PCB layouts.
Technical Context
This Schottky rectifier employs guard ring construction for transient protection and uses low-resistance metal-semiconductor junctions to achieve fast switching (no minority carrier storage) and low conduction loss. Its 300 pF typical junction capacitance at 1 MHz and 4 V reverse bias supports moderate-frequency switching up to ~100 kHz in flyback and buck topologies.
The device operates across –65 °C to +150 °C junction temperature, with derated average current dropping to ~1.8 A at 100 °C ambient on 8.0 mm² copper pads. It is not recommended for new designs; Diodes Incorporated specifies the B3X0 series as its replacement family.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRRM | 30 V - Maximum non-repetitive reverse voltage before breakdown; sets upper limit for output capacitor voltage rating in unregulated supplies. |
| I(AV) | 3.0 A - Average forward current at 25 °C on 8.0 mm² pad; derates to 1.8 A at 100 °C ambient per Fig. 1. |
| VF @ 3.0 A | 0.75 V - Forward drop at full rated current; determines conduction loss (2.25 W max at 3 A) and thermal load. |
| IFSM | 100 A - Non-repetitive surge rating for 8.3 ms half-sine; enables robustness against inrush and short-circuit transients. |
| RJA | 60 °C/W - Junction-to-ambient thermal resistance on standard 8.0 mm² pad; defines required board copper area for thermal management. |
| CT | 300 pF - Junction capacitance at 1 MHz / 4 V reverse bias; impacts EMI and switching losses in high-frequency converters. |
| IR @ 30 V, 25 °C | 0.5 mA - Reverse leakage at rated DC blocking voltage; contributes to standby power loss in offline adapters. |
Pinout & Package
Package: SMC (DO-214AB), molded plastic case with matte tin-plated terminals, moisture sensitivity level 1 per J-STD-020A, approx. weight 0.21 g. Cathode indicated by band.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Input terminal for forward conduction path | Connected to lower-potential side (e.g., switch node in buck sync rectifier or transformer secondary center-tap). |
| Cathode | Output terminal for forward conduction path | Connected to higher-potential rail (e.g., output capacitor positive or VOUT); marked with band on package body. |
Key Features
| Feature | Design Value |
|---|---|
| Guard ring construction | Improves ruggedness against voltage transients and reduces risk of localized avalanche failure during line surges. |
| Low forward voltage (VF ≤ 0.75 V @ 3 A) | Reduces conduction loss by ~30% versus comparable 3 A silicon rectifiers, improving efficiency in 3.3–12 V output stages. |
| High surge capability (IFSM = 100 A) | Withstands repetitive cold-start inrush and short-circuit events without degradation in industrial power modules. |
| UL 94V-0 flammability rating | Meets safety requirements for enclosed power supplies in Class II consumer and industrial equipment. |
Applications
| AC-DC Adapter Output Rectification | Buck Converter Synchronous Rectifier Replacement |
|---|---|
Use Scenario: 5–12 V, 2–3 A wall adapter with universal input (90–264 VAC) and quasi-resonant flyback topology. IC Role / Device Role / Timing Role: Output rectifier diode replacing slower silicon diodes to reduce conduction loss and improve light-load efficiency. Use Value: 0.75 V VF lowers output stage power dissipation by ~1.5 W versus 1.1 V Si diode, reducing heatsink requirement. | Use Scenario: 12 V input to 3.3 V/3 A point-of-load regulator using discrete MOSFET synchronous rectification control. IC Role / Device Role / Timing Role: Freewheeling diode providing body-diode conduction path during high-side FET dead time. Use Value: 300 pF capacitance minimizes shoot-through risk and gate drive loading compared to higher-Cj alternatives. |
| USB-C Power Delivery Front-End Clamp | Industrial Sensor Module Power Input Protection |
Use Scenario: 20 V USB PD source interface with overvoltage clamp and reverse polarity protection before DC-DC regulation. IC Role / Device Role / Timing Role: Reverse-blocking element preventing backfeed from downstream circuitry during hot-plug events. Use Value: 30 V VRRM provides 2× margin over 20 V PD specification, enabling reliable operation under ±10% tolerance. | Use Scenario: 24 V DC-powered industrial sensor node with wide ambient range (−40 to +85 °C) and limited PCB space. IC Role / Device Role / Timing Role: Input polarity protection diode placed between connector and LDO input. Use Value: −65 to +150 °C operating range ensures functionality across full industrial temperature envelope without derating. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Schottky rectifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| B330A-13-F | Same 30 V VRRM, 3 A I(AV), but VF = 0.45 V @ 3 A and RJA = 50 °C/W; SOD-123FL package. | Lower VF improves efficiency in compact designs; smaller footprint requires tighter layout control for thermal relief. | Select when board space is constrained and <0.5 V forward drop is critical for <1 W loss budget. |
| SS33H | 30 V VRRM, 3 A I(AV), VF = 0.52 V @ 3 A, RJA = 55 °C/W; SMB package with higher current density. | Higher thermal performance than SK33-7 on same pad size; optimized for high-reliability automotive-grade supply rails. | Choose for extended temperature operation where 150 °C TJ margin and AEC-Q200 alignment are required. |
Compared with SK33-7, B330A-13-F delivers lower conduction loss in space-constrained layouts, while SS33H offers superior thermal resistance and automotive qualification-both address SK33-7's obsolescence notice with measurable improvements in VF, RJA, or reliability grade.
Availability
SK33-7 is available at Aetrix Electronics and suitable for AC-DC adapters, industrial sensor power inputs, USB-C PD front-end clamping, and buck converter freewheeling paths requiring stable component supply and legacy design continuity.
Supply support for SK33-7 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design centers across Asia and manufacturing in China, Taiwan, and the U.S.
The SKxx series belongs to Diodes' legacy Schottky rectifier product line, designed specifically for cost-sensitive, medium-power AC-DC and DC-DC power conversion where low VF and surge robustness are prioritized over ultra-low leakage or automotive qualification.
FAQ
Is SK33-7 lead-free and RoHS compliant?
Yes, SK33-7 is RoHS compliant and available with matte tin finish plating. The "-F" suffix (e.g., SK33-7-F) explicitly denotes lead-free packaging; standard SK33-7 also meets JEDEC J-STD-020A Level 1 moisture sensitivity and RoHS Directive 2011/65/EU requirements without requiring suffix modification.
What is the maximum allowable junction temperature for continuous operation?
The absolute maximum junction temperature is +150 °C, and the device is rated for continuous operation across –65 °C to +150 °C. Derating begins at 25 °C ambient per Fig. 1: at 100 °C board temperature, average forward current must be reduced to approximately 1.8 A to maintain TJ ≤ 150 °C with RJA = 60 °C/W.
Can SK33-7 replace SK32 or SK34 in an existing design?
Yes, SK33-7 is pin-compatible and mechanically identical to SK32 and SK34 in the SMC package, differing only in VRRM (30 V vs. 20 V or 40 V). Substitution requires verifying that 30 V reverse rating satisfies system overvoltage margins and that forward voltage and thermal behavior align with original design assumptions.
Why is SK33-7 marked "NOT RECOMMENDED FOR NEW DESIGN"?
Diodes Incorporated issued this notice because the B3X0 series offers improved VF (e.g., B330A: 0.45 V), lower RJA, and enhanced process control. SK33-7 remains fully functional and supported for legacy production, but new designs should evaluate B330A-13-F or SS33H for better efficiency, thermal performance, or qualification status.
SK33-7 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- DO-214AB, SMC
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- 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:
- 300pF @ 4V, 1MHz
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMC
- Operating Temperature - Junction:
- -65°C ~ 150°C
SK33-7 FAQ
1.How can I place an order for SK33-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for SK33-7 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 SK33-7 reliable?
The price and inventory of SK33-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SK33-7 is usually 5 days.
3.What payment methods are accepted for SK33-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SK33-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SK33-7?
SK33-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SK33-7 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 SK33-7?
For technical support, including SK33-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SK33-7 requirements.
6.How does Aetrix verify that SK33-7 is sourced from the original manufacturer or authorized distributors?
All SK33-7 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 SK33-7 meets industry standards.
7.What is the process for return or replacement of SK33-7?
All SK33-7 units undergo pre-shipment inspection (PSI). If there is an issue with SK33-7, 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 SK33-7 part is unused and in its original packaging.
Return procedure for SK33-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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