SM15T18A STMicroelectronics TVS Diode (Uni-directional) (Diodes Moulded) In Stock
STMicroelectronics SM15T18A is a 1500 W unidirectional transient voltage suppressor (TVS) diode with an 18 V nominal breakdown voltage and a 32.5 V maximum clamping voltage in a 2-pin SMC package. It provides fast-response overvoltage protection for sensitive electronics against ESD and surge transients. Available worldwide with prompt shipping.
- Manufacturer
- STMicroelectronics
- Package
- Diodes Moulded
- Pin Count
- 2
- Lifecycle
- ACTIVE
- Datasheet
- SM15T18A Datasheet PDF
- Category
- TVS Diode (Uni-directional)
- Price
- From $0.2178(MOQ 10)
- Temp Range
- -55.0°C to 150.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- 1500 W peak pulse power dissipation with a 32.5 V maximum clamping voltage protects downstream circuits from high-energy transient events in industrial and automotive environments
- 18 V nominal breakdown voltage with tight ±5% tolerance (17.1 V to 18.9 V) ensures precise overvoltage clamping on 12 V and 15 V supply rails
- UL-recognized SMC (DO-214AB) package enables compact, low-inductance board-level transient protection without bulky through-hole TVS components
Applications
The SM15T18A is used on the input supply rails of industrial I/O modules, motor drives, and 12 V automotive electronic control units to clamp load-dump and inductive switching transients to a safe 32.5 V level. Telecom and datacom line-card power inputs protected by the SM15T18A benefit from its 1500 W capability that absorbs energy from EFT (electrical fast transient) events per IEC 61000-4-4. It is also placed across RS-485 and CAN bus transceivers to divert surge energy before it reaches the IC input pins.
Specifications
| Factory Lead Time | 53 Weeks, 1 Day |
| YTEOL | 7.06 |
| Additional Feature | UL RECOGNIZED |
| Breakdown Voltage-Max | 18.9V |
| Breakdown Voltage-Min | 17.1V |
| Breakdown Voltage-Nom | 18V |
| Clamping Voltage-Max | 32.5V |
| Configuration | SINGLE, 1 CHANNEL |
| Diode Element Material | SILICON |
| Diode Type | TRANS VOLTAGE SUPPRESSOR DIODE |
| JEDEC-95 Code | DO-214AB |
| JESD-30 Code | R-PDSO-C2 |
| JESD-609 Code | e3 |
| Non-rep Peak Rev Power Dis-Max | 1500W |
| Number of Elements | 1 |
| Package Body Material | PLASTIC/EPOXY |
| Package Shape | RECTANGULAR |
| Package Style | SMALL OUTLINE |
| Peak Reflow Temperature (Cel) | 260 |
| Polarity | UNIDIRECTIONAL |
| Qualification Status | Not Qualified |
| Reference Standard | IEC-61000-4-2, 4-4, 4-5; MIL-STD-750; MIL-STD-883 |
| Rep Pk Reverse Voltage-Max | 15.3V |
| Reverse Current-Max | 5 µ A |
| Reverse Test Voltage | 15.3V |
| Surface Mount | YES |
| Technology | AVALANCHE |
| Terminal Finish | Matte Tin (Sn) - annealed |
| Terminal Form | C BEND |
| Terminal Position | DUAL |
| Time@Peak Reflow Temperature-Max (s) | 30 |
| Package | Diodes Moulded |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| Moisture Sensitivity Level | MSL 1 |
| ECCN | EAR99 |
| HTS Code | 8541.10.00.50 |
| Country of Origin | Mainland China |
Alternate & Equivalent Parts
No known alternates. Submit an RFQ and our team can suggest alternatives.
Frequently Asked Questions
What is the peak pulse power rating of the SM15T18A, and over what transient pulse duration is it specified?
The SM15T18A is rated for 1500 W peak pulse power dissipation, typically measured over a 10 µs/1000 µs standard transient waveform (10 µs rise, 1000 µs decay). This 1500 W rating allows the device to absorb high-energy surges from inductive switching and automotive load-dump events without permanent damage.
What clamping voltage does the SM15T18A guarantee, and why does it matter for protecting a 12 V system rail?
The SM15T18A clamps transients to a maximum of 32.5 V under its rated 1500 W pulse condition. For a 12 V automotive or industrial system, downstream ICs typically withstand absolute maximum voltages of 36 V to 40 V. The 32.5 V clamp ensures the protected rail stays below these limits during 100 V or higher load-dump transients, preventing IC latch-up or permanent damage.
How does the SMC package of the SM15T18A benefit high-frequency transient protection compared to a through-hole TVS diode?
The SMC (DO-214AB) surface-mount package of the SM15T18A provides lower parasitic lead inductance (typically below 5 nH) compared to axial through-hole TVS packages (10 nH to 20 nH). Lower inductance means the clamping diode responds faster to ESD and EFT spike edges with sub-nanosecond rise times, providing more effective protection for high-speed signal and power lines at frequencies above 100 MHz.
When should the SM15T18A be chosen over a bidirectional TVS diode for protecting a DC power rail in an industrial controller?
On unipolar DC supply rails such as a 12 V or 15 V bus, a unidirectional TVS like the SM15T18A is preferred because it has a lower forward-conduction threshold in the reverse avalanche direction, enabling faster and more efficient clamping of positive surges. A bidirectional device would add unnecessary forward-conduction resistance on the negative half of a transient that cannot exist on a DC rail, wasting clamping headroom and increasing the peak let-through voltage above the required 32.5 V maximum.
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About STMicroelectronics
STMicroelectronics is a global semiconductor leader serving customers across the spectrum of electronics applications. ST's products are found in a wide range of applications including automotive, industrial, personal electronics, and communications.
| Qty. | Unit Price | Ext. Price |
|---|---|---|
| 10+ | $0.8500 | $8.50 |
| 50+ | $0.6680 | $33.40 |
| 100+ | $0.6100 | $61.00 |
| 250+ | $0.2681 | $67.03 |
| 500+ | $0.2346 | $117.30 |
| 1000+ | $0.2178 | $217.80 |
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