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STMicroelectronics SMTYF18A
- Part No.:
- SMTYF18A
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-221AC, SMA Flat Leads
- Datasheet:
-
SMTYF18A.pdf
- Description:
- TVS DIODE 18VWM SMA
- Quantity:
- Payment:
- Shipping:
Inventory:8,901
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Product details
Overview
SMTYF12A from STMicroelectronics is a unidirectional low-forward-voltage TVS diode combining transient suppression and Schottky rectification in a monolithic SMAflat package. It features 12 V stand-off voltage, 0.48 V forward voltage at 0.85 A, 18.5 V clamping voltage at 1 A (10/1000 µs), 22.9 V clamping at 1 A (8/20 µs), and 4000 W peak pulse power (8/20 µs), designed for ESD protection in portable USB interfaces.
For engineers reviewing the SMTYF12A datasheet, SMTYF12A pinout, SMTYF12A application, or SMTYF12A equivalent, key selection criteria include clamping ratio (VCL/VBR = 1.91), junction capacitance (<100 pF @ 1 V), thermal resistance (20 °C/W junction-to-leads), and ECOPACK2® halogen-free compliance for space-constrained consumer electronics.
Technical Context
The SMTYF12A integrates a Transil™-type avalanche breakdown structure with a low-VF Schottky junction, enabling simultaneous ESD clamping and DC path conduction. Its 12 V stand-off voltage ensures compatibility with 12 V signal rails while maintaining margin against normal operating transients.
Clamping behavior follows VCL = RD × IPP + VBR(max), with dynamic resistance of 0.055 Ω (8/20 µs) and 0.129 Ω (10/1000 µs). The device meets IEC 61000-4-2 Level 4 (±15 kV air / ±8 kV contact) and MIL-STD-883E Class 3C HBM requirements.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRM) | 12 V - defines maximum continuous reverse operating voltage before leakage exceeds 20 µA |
| Breakdown Voltage (VBR) | 13.2–14.3 V @ 1 mA - specifies avalanche onset threshold for reliable transient clamping |
| Clamping Voltage (VCL) | 18.5 V @ 1 A (10/1000 µs) - limits downstream voltage during surge to protect 12 V logic interfaces |
| Forward Voltage (VF) | 0.48 V @ 0.85 A - enables low-loss DC power path integration without adding series diode drop |
| Peak Pulse Power | 4000 W @ 8/20 µs - sustains high-energy lightning surges per IEC 61000-4-5 waveform |
| Junction Capacitance | <100 pF @ 1 V - preserves signal integrity in high-speed data lines (e.g., USB 2.0) |
| Package Height | 1.0 mm max - fits ultra-thin mobile PCBs with strict Z-axis clearance constraints |
Pinout & Package
Package: SMAflat (JEDEC DO-221AC), surface-mount, unidirectional, cathode indicated by band. Overall height ≤1.0 mm, footprint optimized for FR4 PCB with 35 µm copper.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (A) | Input/Source terminal for forward conduction path | Connects to protected line (e.g., USB VBUS); conducts current when forward-biased below 0.48 V |
| Cathode (K) | Output/Sink terminal; marked by band | Connects to ground or return path; initiates avalanche clamping when reverse voltage exceeds 13.2 V |
Key Features
| Feature | Design Value |
|---|---|
| Monolithic Transil + Schottky integration | Eliminates need for discrete TVS + Schottky pair, reducing BOM count and board area in portable designs |
| Low clamping factor (VCL/VBR ≈ 1.91) | Minimizes overvoltage stress on downstream ICs compared to standard TVS diodes with ratios >2.2 |
| ECOPACK2® halogen-free construction | Meets RoHS and JEDEC JESD97 marking standards without compromising thermal performance (Rth(j-l) = 20 °C/W) |
| Fast response time (<1 ns) | Clamps ESD events before damage occurs to sensitive CMOS inputs in handheld devices |
Applications
| USB 2.0 VBUS Protection | Automotive Infotainment Display Interface |
|---|---|
Use Scenario: Protecting USB host port VBUS line from hot-plug inrush and ESD events during cable insertion. IC Role / Device Role / Timing Role: Unidirectional TVS + low-VF rectifier integrated into single component on VBUS rail. Use Value: Clamps surges to ≤18.5 V while adding only 0.48 V forward drop-preserving 5 V regulation margin and eliminating separate Schottky diode. | Use Scenario: Safeguarding LVDS or FPD-Link video data lines in automotive center-stack displays exposed to ESD during service access. IC Role / Device Role / Timing Role: Bidirectional-capable protection element placed at connector interface with low capacitance <100 pF. Use Value: Maintains signal integrity up to 480 Mbps while meeting ISO 10605 30 kV air discharge requirement via low dynamic resistance (0.055 Ω). |
| Smartphone Charging Port | Industrial Handheld Scanner |
Use Scenario: Securing micro-USB or USB-C CC/VCONN lines against repeated ESD exposure in consumer charging ports. IC Role / Device Role / Timing Role: Standoff-rated (12 V) unidirectional suppressor placed between connector and PMIC input. Use Value: Survives ≥10,000 contact discharges per IEC 61000-4-2 Level 4 due to robust silicon structure and 175 °C max junction temperature rating. | Use Scenario: Protecting RS-485 communication lines in ruggedized barcode scanners used in warehouse environments. IC Role / Device Role / Timing Role: High-power transient suppressor on differential bus lines with 4000 W (8/20 µs) capability. Use Value: Withstands induced surges from nearby motor switching without degradation-validated per MIL-STD-883E Class 3C HBM. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar low-VF TVS applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ12A | Standard TVS only (no Schottky function); VF not specified; VCL = 19.9 V @ 1 A (10/1000 µs) | Requires external Schottky diode for DC path; higher clamping increases risk to 12 V logic | Select when cost priority outweighs board space and dual-function integration |
| P6SMB12CA | Bi-directional; no low-VF capability; VCL = 19.2 V @ 1 A (10/1000 µs); C = 250 pF | Unsuitable for DC-coupled lines requiring forward conduction; higher capacitance degrades high-speed signals | Choose only for AC-coupled or symmetric transient paths where polarity reversal is possible |
Compared with SMAJ12A and P6SMB12CA, SMTYF12A uniquely delivers combined ESD suppression and low-loss power path functionality in one die, reducing system-level component count and improving reliability in space-constrained portable designs.
Availability
SMTYF12A is available at Aetrix Electronics and suitable for USB interface protection, industrial handheld scanners, automotive infotainment displays, and smartphone charging ports requiring stable component supply across production lifecycles.
Supply support for SMTYF12A 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.
The SMTYF series belongs to ST's Transky™ family-engineered specifically for miniaturized portable electronics needing co-integrated ESD protection and efficient DC conduction in sub-1 mm profiles.
FAQ
What is the maximum operating junction temperature for SMTYF12A?
The SMTYF12A has an operating junction temperature range of –40 °C to +175 °C, validated per absolute ratings table. This allows reliable operation in automotive under-hood environments and industrial enclosures with minimal heatsinking, supported by its 20 °C/W junction-to-leads thermal resistance.
Does SMTYF12A meet automotive qualification standards?
SMTYF12A is not AEC-Q200 qualified and is not rated for automotive safety-critical systems. However, its –40 °C to +175 °C operating range, IEC 61000-4-2 Level 4 ESD immunity, and MIL-STD-883E Class 3C HBM compliance make it suitable for non-safety infotainment and body electronics where full automotive qualification is not mandated.
How does the low forward voltage benefit circuit design?
The 0.48 V forward voltage at 0.85 A eliminates the need for a separate Schottky diode in DC power paths, reducing component count, PCB area, and forward voltage drop in battery-powered devices. This directly extends runtime in portable equipment and avoids cumulative voltage loss in cascaded power rails.
Can SMTYF12A be used in bidirectional signal lines?
No-SMTYF12A is unidirectional, with cathode marked by a band. For bidirectional data lines like USB D+/D–, use a dedicated low-capacitance bidirectional TVS such as ESDALC6V1-1U2. SMTYF12A is intended for unidirectional rails like VBUS, power supplies, or single-ended control signals.
SMTYF18A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-221AC, SMA Flat Leads
- Series:
- SMTY, Transky™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 18V
- Voltage - Breakdown (Min):
- -
- Voltage - Clamping (Max) @ Ipp:
- -
- Current - Peak Pulse (10/1000µs):
- -
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -40°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMA
SMTYF18A FAQ
1.How can I place an order for SMTYF18A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMTYF18A 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 SMTYF18A reliable?
The price and inventory of SMTYF18A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMTYF18A is usually 5 days.
3.What payment methods are accepted for SMTYF18A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMTYF18A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMTYF18A?
SMTYF18A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMTYF18A 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 SMTYF18A?
For technical support, including SMTYF18A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMTYF18A requirements.
6.How does Aetrix verify that SMTYF18A is sourced from the original manufacturer or authorized distributors?
All SMTYF18A 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 SMTYF18A meets industry standards.
7.What is the process for return or replacement of SMTYF18A?
All SMTYF18A units undergo pre-shipment inspection (PSI). If there is an issue with SMTYF18A, 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 SMTYF18A part is unused and in its original packaging.
Return procedure for SMTYF18A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMTYF18A Tags
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