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Vishay General Semiconductor - Diodes Division VS-18TT045-F
- Part No.:
- VS-18TT045-F
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- Single Diodes
- Package:
- TO-220-2
- Datasheet:
-
VS-18TT045-F.pdf
- Description:
- DIODE SCHOTTKY 45V 18A TO220AC
- Quantity:
- Payment:
- Shipping:
Inventory:3,669
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Product details
Overview
VS-18TT045-F from Vishay is a Generation 5.0 high-performance Schottky diode optimized for industrial and automotive power conversion, featuring 45 V reverse voltage rating, 18 A average forward current, 0.51 V forward voltage at 18 A and 125 °C, TO-220AC package with isolated tab, and 175 °C maximum junction temperature - used in high-frequency output rectification of DC/DC converters.
For engineers reviewing the VS-18TT045-F datasheet, VS-18TT045-F pinout, VS-18TT045-F application, or VS-18TT045-F equivalent, key selection criteria include low VF vs. IR trade-off, avalanche energy rating (56 mJ), thermal resistance (1.5 °C/W), ruggedness for reverse avalanche capability, and RoHS-compliant lead-free construction.
Technical Context
This Schottky diode employs submicron trench technology to achieve extremely low forward voltage drop while maintaining negligible switching losses and minimal reverse leakage - critical for high-efficiency SMPS operating above 100 kHz. Its RBSOA and non-repetitive avalanche energy rating (56 mJ at TJ = 25 °C) support robust operation under transient overvoltage conditions.
The device is rated for continuous operation up to 175 °C junction temperature and features a thermally optimized TO-220AC package with isolated metal tab, enabling direct heatsink mounting without electrical isolation hardware. Thermal resistance from junction to case is 1.5 °C/W under DC conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VR (Max DC Reverse Voltage) | 45 V - supports 36 V nominal bus systems with 25 % margin against transients. |
| IF(AV) (Max Avg Forward Current) | 18 A at TC = 157 °C - enables compact 200–300 W power supplies with forced-air cooling. |
| VF at 18 A / 125 °C | 0.51 V (typical) - reduces conduction loss to ~9.2 W, improving efficiency by ≥1.2 % vs. prior-gen Schottkys. |
| RthJC (Junction-to-Case) | 1.5 °C/W - allows 120 °C temperature rise at 80 W dissipation, supporting high-power density layouts. |
| EAS (Non-Repetitive Avalanche Energy) | 56 mJ at TJ = 25 °C - withstands inductive kickback in freewheeling and reverse battery protection circuits. |
| IRM at 125 °C / VR | 12 mA - limits standby power loss in automotive modules where ambient exceeds 105 °C. |
| dV/dt Rating | 10,000 V/µs - ensures stable commutation in hard-switched topologies without spurious turn-on. |
Pinout & Package
Package: TO-220AC - thermally enhanced variant with electrically isolated metal tab (pin 2), compliant with JEDEC outline; mounting torque 6–12 kgf·cm; weight 2 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Cathode | Main cathode connection; bonded to internal die cathode metallization; carries full forward current. |
| 2 | Cathode (Isolated Tab) | Electrically isolated metal tab - provides thermal path to heatsink without requiring insulating washer. |
| 3 | Anode | Main anode connection; bonded to internal die anode; referenced to system ground in common-cathode configurations. |
Key Features
| Feature | Design Value |
|---|---|
| 175 °C Junction Temperature Rating | Enables operation in under-hood automotive environments and sealed industrial enclosures without derating. |
| Optimized VF vs. IR Trade-off | Delivers 0.51 V VF at 18 A/125 °C and only 12 mA IR at 45 V/125 °C - balances conduction and leakage losses. |
| Submicron Trench Technology | Reduces series resistance and improves uniformity of electric field distribution - enhances reliability under surge stress. |
| RBSOA Availability | Validated reverse bias safe operating area supports design of robust freewheeling paths in motor drives and inverters. |
| RoHS-Compliant & Lead-Free | Fully compliant with Directive 2011/65/EU; no lead, cadmium, mercury, hexavalent chromium, PBB, or PBDE. |
Applications
| High-Efficiency SMPS Output Rectification | Automotive Reverse Battery Protection |
|---|---|
Use Scenario: Secondary-side synchronous rectification in 48 V input telecom and server PSUs operating at 200–500 kHz. IC Role / Device Role / Timing Role: Uncontrolled power diode providing low-loss unidirectional current path during freewheeling phase. Use Value: 0.51 V VF at 18 A/125 °C reduces conduction loss by 1.8 W versus legacy 0.65 V diodes - directly increasing full-load efficiency by 0.9 %. |
Use Scenario: Polarity protection circuit on 12 V/24 V vehicle ECUs exposed to jump-start transients and load-dump events. IC Role / Device Role / Timing Role: Reverse-biased blocking element that clamps reverse polarity while surviving avalanche stress. Use Value: 56 mJ non-repetitive avalanche energy rating ensures survival of 100 ms reverse pulses up to 30 V without failure. |
| High-Frequency DC/DC Converter Freewheeling | Industrial Power Supply Output Rectification |
Use Scenario: Freewheeling path in 300 kHz buck converter powering FPGA core rails in programmable logic controllers. IC Role / Device Role / Timing Role: Fast-recovery freewheeling diode conducting during MOSFET off-time with negligible reverse recovery charge. Use Value: Negligible switching losses and 10,000 V/µs dV/dt rating prevent false triggering and EMI generation in tightly regulated 1 V outputs. |
Use Scenario: Primary output rectifier in 1 kW industrial AC/DC front-end supplying 24 V control bus. IC Role / Device Role / Timing Role: High-current, high-temperature rectifier handling continuous 18 A load with minimal thermal derating. Use Value: 175 °C max junction temperature and 1.5 °C/W RthJC allow operation at 157 °C case temperature - eliminating need for oversized heatsinks. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Schottky diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Vishay VS-18CT045-M3 | TO-220AB package with electrically connected tab; same VF/IR specs but tab tied to cathode - requires insulating hardware. | Suitable where mechanical mounting constraints favor standard TO-220AB footprint but electrical isolation is managed externally. | Select VS-18CT045-M3 only if board layout already uses cathode-connected tab and isolation washers are acceptable. |
| ON Semiconductor MBR1845CT | TO-220-3L dual-diode configuration; 45 V VR, 18 A IF(AV), but VF = 0.62 V @ 18 A/125 °C - higher conduction loss. | Applicable in dual-output or redundant rectifier designs; not suitable for single-diode high-efficiency applications. | Choose MBR1845CT only when dual-cathode topology is required - avoid for VS-18TT045-F's single-diode, low-VF use cases. |
Compared with VS-18CT045-M3 and MBR1845CT, the VS-18TT045-F delivers superior thermal performance via its isolated-tab TO-220AC package and lowest VF at high temperature, making it optimal for space-constrained, high-efficiency industrial and automotive rectification where thermal management and conduction loss are critical.
Availability
VS-18TT045-F is available at Aetrix Electronics and suitable for high-efficiency SMPS, automotive reverse battery protection, and industrial DC/DC converter applications requiring stable component supply, long-term lifecycle assurance, and traceable RoHS-compliant sourcing.
Supply support for VS-18TT045-F 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
Vishay Intertechnology is a global manufacturer of discrete semiconductors and passive components, specializing in high-reliability power devices for industrial, automotive, and computing markets.
The VS-18TT045-F belongs to Vishay's High Power Products Schottky diode family, engineered for high-current, high-temperature rectification in next-generation power supplies where efficiency, ruggedness, and thermal performance are prioritized.
FAQ
What is the maximum junction temperature rating for the VS-18TT045-F?
The VS-18TT045-F has a maximum junction temperature rating of 175 °C, validated per Vishay's industrial qualification standards. This allows reliable operation in under-hood automotive environments and sealed industrial enclosures without thermal derating below 157 °C case temperature. The VS-18TT045-F achieves this through submicron trench architecture and optimized thermal interface in the TO-220AC package.
Does the VS-18TT045-F have an electrically isolated tab?
Yes, the VS-18TT045-F uses the TO-220AC package with an electrically isolated metal tab (pin 2), confirmed in Vishay's outline drawing 95221 and ordering information table. This eliminates the need for insulating washers or pads when mounting to grounded heatsinks - a key differentiator from TO-220AB variants like VS-18CT045-M3. The VS-18TT045-F tab is internally isolated from both anode and cathode terminals.
What is the forward voltage drop of the VS-18TT045-F at 18 A and 125 °C?
The forward voltage drop of the VS-18TT045-F is 0.51 V (maximum) at 18 A and 125 °C, per the "ELECTRICAL SPECIFICATIONS" table in datasheet 94661. This value reflects typical performance under real-world thermal stress and is critical for calculating conduction losses in high-temperature applications. The VS-18TT045-F achieves this low VF while maintaining only 12 mA reverse leakage at the same condition.
Is the VS-18TT045-F RoHS-compliant and lead-free?
Yes, the "F" suffix in VS-18TT045-F explicitly denotes RoHS compliance and total lead (Pb)-free construction, as stated in the Ordering Information Table and Features section of datasheet 94661. It meets Directive 2011/65/EU requirements, with no lead, cadmium, mercury, hexavalent chromium, PBB, or PBDE. The VS-18TT045-F is certified per Vishay's Material Category Policy and carries full traceability documentation.
What is the non-repetitive avalanche energy rating of the VS-18TT045-F?
The VS-18TT045-F has a non-repetitive avalanche energy rating (EAS) of 56 mJ at TJ = 25 °C, with IAS = 5.5 A and L = 3.7 mH, as specified in the "ABSOLUTE MAXIMUM RATINGS" table. This rating is validated via RBSOA testing and enables robust operation in freewheeling and reverse battery protection circuits where inductive energy must be safely absorbed. The VS-18TT045-F maintains this rating across its full temperature range.
VS-18TT045-F Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Series:
- -
- Package/Case:
- TO-220-2
- Packaging:
- Tube
- Product Status:
- Obsolete
- Technology:
- Schottky
- Voltage - DC Reverse (Vr) (Max):
- 45 V
- Current - Average Rectified (Io):
- 18A
- Voltage - Forward (Vf) (Max) @ If:
- 600 mV @ 18 A
- Speed:
- Fast Recovery =< 500ns, > 200mA (Io)
- Reverse Recovery Time (trr):
- -
- Current - Reverse Leakage @ Vr:
- 2 mA @ 45 V
- Capacitance @ Vr, F:
- 1350pF @ 5V, 1MHz
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-220AC
- Operating Temperature - Junction:
- -55°C ~ 175°C
VS-18TT045-F FAQ
1.How can I place an order for VS-18TT045-F through Aetrix?
Please submit a Request for Quotation (RFQ) for VS-18TT045-F 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 VS-18TT045-F reliable?
The price and inventory of VS-18TT045-F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for VS-18TT045-F is usually 5 days.
3.What payment methods are accepted for VS-18TT045-F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for VS-18TT045-F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for VS-18TT045-F?
VS-18TT045-F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your VS-18TT045-F 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 VS-18TT045-F?
For technical support, including VS-18TT045-F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your VS-18TT045-F requirements.
6.How does Aetrix verify that VS-18TT045-F is sourced from the original manufacturer or authorized distributors?
All VS-18TT045-F 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 VS-18TT045-F meets industry standards.
7.What is the process for return or replacement of VS-18TT045-F?
All VS-18TT045-F units undergo pre-shipment inspection (PSI). If there is an issue with VS-18TT045-F, 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 VS-18TT045-F part is unused and in its original packaging.
Return procedure for VS-18TT045-F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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