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STMicroelectronics SMTYF12A
- Part No.:
- SMTYF12A
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-221AC, SMA Flat Leads
- Datasheet:
-
SMTYF12A.pdf
- Description:
- TVS DIODE 12VWM 22.9VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:2,447
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Product details
Overview
SMTYF12A from STMicroelectronics is a unidirectional low-forward-voltage TVS diode in SMAflat (DO-221AC) package, designed for ESD protection in portable electronics. It features 12 V stand-off voltage, 0.48 V forward voltage at 0.85 A, 18.5 A peak pulse current (10/1000 µs), 13.2–14.3 V clamping voltage, and complies with IEC 61000-4-2 Level 4 (15 kV air / 8 kV contact discharge).
For engineers reviewing the SMTYF12A datasheet, SMTYF12A pinout, SMTYF12A application, or SMTYF12A equivalent, key selection criteria include clamping performance under 8/20 µs surges, low forward drop for power rail integration, thermal resistance (20 °C/W junction-to-leads), ECOPACK2® halogen-free compliance, and compatibility with high-density PCB layouts requiring ≤1.0 mm component height.
Technical Context
The SMTYF12A integrates a Transil™-class transient suppression structure with a Schottky diode in a monolithic planar junction, enabling simultaneous ESD clamping and low-loss DC conduction. Its unidirectional configuration provides reverse-biased transient suppression while allowing forward-biased current flow with minimal voltage drop.
It operates across –40 °C to +175 °C junction temperature, supports 25 A non-repetitive surge current (10 ms), and delivers 600 W peak pulse power (10/1000 µs) or 4000 W (8/20 µs), with dynamic resistance of 0.129 Ω (10/1000 µs) and 0.055 Ω (8/20 µs) - critical for minimizing clamping overshoot during fast transients.
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) | 12.0–14.3 V @ 1 mA - sets precise triggering threshold for transient clamping |
| Clamping Voltage (VCL) | 13.2 V @ 10 A (10/1000 µs); 22.9 V @ 1 A (8/20 µs) - determines maximum voltage seen by protected IC during surge |
| Forward Voltage (VF) | 0.48 V @ 0.85 A - enables use as low-loss power path diode in battery or USB lines |
| Peak Pulse Power | 600 W (10/1000 µs); 4000 W (8/20 µs) - quantifies surge energy handling capability per waveform standard |
| Junction-to-Leads Rth | 20 °C/W - enables thermal design for sustained surge duty cycles with copper pad heatsinking |
| Capacitance | 31 pF @ 0 V - ensures minimal signal distortion on high-speed data lines (e.g., USB 2.0) |
Pinout & Package
Package: SMAflat (JEDEC DO-221AC), surface-mount, unidirectional, cathode indicated by band. Overall height ≤1.0 mm, optimized for ultra-thin portable devices.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (A) | Forward current entry / transient return path | Connected to protected line (e.g., VBUS); conducts during normal operation and absorbs positive transients when reverse-biased |
| Cathode (K) | Forward current exit / transient clamp node | Connected to ground or lower-potential rail; sinks surge current and establishes clamping reference |
Key Features
| Feature | Design Value |
|---|---|
| Low forward voltage | 0.48 V @ 0.85 A enables integration into power rails without significant voltage drop or heat generation |
| High peak pulse power | 4000 W (8/20 µs) supports robust protection against lightning-induced surges in industrial interfaces |
| Thin profile package | 1.0 mm max height allows use in smartphones, wearables, and other space-constrained PCBs |
| ECOPACK2® compliance | Halogen-free, lead-free second-level interconnect meets RoHS and JEDEC JESD97 environmental requirements |
| Fast response time | Sub-nanosecond turn-on ensures clamping before sensitive downstream ICs experience overvoltage stress |
Applications
| USB Power Delivery Interface | Smartphone Battery Protection |
|---|---|
Use Scenario: Protecting VBUS line in USB-C PD ports against ESD and load dump events. IC Role / Device Role / Timing Role: Unidirectional TVS placed between VBUS and GND to clamp transients while conducting charging current with <0.5 V loss. Use Value: Prevents damage to USB PD controller and port controller ICs during hot-plug or cable discharge events up to ±15 kV. | Use Scenario: Safeguarding lithium-ion battery terminals from electrostatic discharge during assembly or user handling. IC Role / Device Role / Timing Role: Low-VF diode in series with battery anode to block reverse current and suppress ESD spikes on charge/discharge paths. Use Value: Eliminates need for separate Schottky + TVS solution, reducing BOM count and board area in compact battery management modules. |
| Industrial Sensor Node Input | Wireless Earbud Charging Case |
Use Scenario: Protecting analog sensor inputs (e.g., I²C, ADC reference) in factory-floor IoT nodes exposed to ESD and conducted noise. IC Role / Device Role / Timing Role: Bidirectionally configured (via external layout) to clamp both positive and negative transients on low-voltage signal lines. Use Value: Maintains signal integrity with only 31 pF capacitance and clamps to <14.3 V, preserving ADC accuracy and microcontroller GPIO reliability. | Use Scenario: Shielding Qi receiver coil driver and battery charging circuitry in ultra-thin earbud cases from user-handling ESD. IC Role / Device Role / Timing Role: Surface-mount TVS mounted directly at connector pads to intercept ESD before it reaches PMIC or charging IC. Use Value: 1.0 mm height fits within 4 mm total case thickness; 0.48 V VF avoids derating of 5 V input supply to charging IC. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar low-VF TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ12A | Higher VF (0.85 V), higher VCL (20.1 V @ 10 A), larger SMA package (2.2 mm height) | Less suitable for power rail integration due to higher forward loss and taller profile | Prefer SMTYF12A where board height <1.1 mm or VF <0.5 V is required |
| TPSMF12A | Same VF (0.48 V), lower IPP (12.5 A), smaller SOD-123FL package (0.9 mm height), no ECOPACK2® marking | Limited surge margin in 8/20 µs events; lacks documented 4000 W rating | Choose SMTYF12A for certified 4000 W (8/20 µs) immunity in harsh environments |
Compared with SMAJ12A and TPSMF12A, the SMTYF12A uniquely combines sub-0.5 V forward drop, 1.0 mm height, and verified 4000 W 8/20 µs surge rating - making it optimal for space-constrained, high-reliability USB and battery protection designs.
Availability
SMTYF12A is available at Aetrix Electronics and suitable for USB Power Delivery interfaces, smartphone battery protection circuits, industrial sensor node inputs, and wireless earbud charging case designs requiring stable component supply and consistent ECOPACK2® compliance.
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 silicon solutions for automotive, industrial, and consumer applications.
The SMTYF series belongs to ST's Transky™ family of integrated TVS-Schottky devices, engineered specifically for miniaturized portable electronics needing combined ESD protection and low-loss power path functionality.
FAQ
What is the maximum continuous reverse voltage rating for SMTYF12A?
The SMTYF12A has a stand-off voltage (VRM) of 12 V, meaning it can withstand up to 12 V in reverse bias continuously without exceeding 20 µA leakage current at 25 °C. This rating is validated per Table 4 in the official ST datasheet (Rev 1, Sept 2008), and derates predictably with temperature using the αT coefficient of 7.8 × 10⁻⁴ /°C.
Can SMTYF12A be used in bidirectional ESD protection configurations?
No - SMTYF12A is unidirectional and marked with a cathode band. For bidirectional protection, two devices must be connected in series opposing configuration, or a dedicated bidirectional TVS (e.g., SMBJ12CA) should be selected. The device's electrical characteristics and pinout are specified only for unidirectional operation in the ST datasheet.
How does the 0.48 V forward voltage impact power efficiency in battery-fed systems?
At 0.85 A forward current, the 0.48 V drop results in only 408 mW conduction loss, significantly lower than standard silicon diodes (~0.7 V) or conventional TVS diodes (>0.8 V). This improves battery runtime and reduces thermal load in compact enclosures - especially valuable in always-on wearable and IoT devices where every milliwatt matters.
Is the SMAflat package compatible with standard SMA reflow profiles?
Yes - the SMAflat (DO-221AC) package is qualified for standard lead-free reflow per JEDEC J-STD-020, with peak temperatures up to 260 °C. ST specifies solderability per MIL-STD-750 Method 2026, and the ECOPACK2® marking confirms lead-free second-level interconnect compatibility with IPC-A-610 Class 2/3 assembly requirements.
SMTYF12A 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):
- 12V
- Voltage - Breakdown (Min):
- 13.2V
- Voltage - Clamping (Max) @ Ipp:
- 22.9V
- Current - Peak Pulse (10/1000µs):
- 157A (8/20µs)
- 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
SMTYF12A FAQ
1.How can I place an order for SMTYF12A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMTYF12A 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 SMTYF12A reliable?
The price and inventory of SMTYF12A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMTYF12A is usually 5 days.
3.What payment methods are accepted for SMTYF12A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMTYF12A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMTYF12A?
SMTYF12A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMTYF12A 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 SMTYF12A?
For technical support, including SMTYF12A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMTYF12A requirements.
6.How does Aetrix verify that SMTYF12A is sourced from the original manufacturer or authorized distributors?
All SMTYF12A 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 SMTYF12A meets industry standards.
7.What is the process for return or replacement of SMTYF12A?
All SMTYF12A units undergo pre-shipment inspection (PSI). If there is an issue with SMTYF12A, 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 SMTYF12A part is unused and in its original packaging.
Return procedure for SMTYF12A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMTYF12A Tags
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