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onsemi SMS12T1
- Part No.:
- SMS12T1
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- SC-74, SOT-457
- Datasheet:
-
SMS12T1.pdf
- Description:
- TVS DIODE 12VWM 23VC SC74
- Quantity:
- Payment:
- Shipping:
Inventory:7,305
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Product details
Overview
SMS12T1 from onsemi is a quad unidirectional ESD and surge protector in SC-74 package, rated for 12 V working peak reverse voltage (VRWM), 19.0 V clamping voltage (VC) at 15 A peak pulse current, and 350 W peak pulse power (8 × 20 µs). It delivers Class N ESD protection (>25 kV HBM), IEC 61000-4-2 (15 kV air/8 kV contact), and IEC 61000-4-5 (23 A surge), targeting USB data lines and I/O ports in portable electronics.
For engineers reviewing the SMS12T1 datasheet, pinout, applications, or equivalent options, key selection criteria include its 12 V VRWM tolerance, low 80–150 pF capacitance at 0 V bias, 1.0 µA max reverse leakage at VRWM, and verified SC-74 pin-compatible layout for quad-channel transient suppression in space-constrained interfaces.
Technical Context
The SMS12T1 integrates four independent unidirectional TVS diodes in a single SC-74 (Case 318F) monolithic silicon die. Each channel features a Zener-based avalanche structure optimized for fast response (<1 ns) to ESD transients and robust 8/20 µs surge handling up to 23 A.
Its electrical behavior is defined by precise breakdown voltage (VBR = 13.3–15.0 V @ 1 mA), tightly controlled clamping (VC = 19.0 V @ IPP = 15 A), and low dynamic impedance-enabling effective overvoltage limiting without signal distortion in high-speed digital lines.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 12 V - Maximum continuous reverse operating voltage before clamping begins; sets safe interface voltage margin for 12 V nominal systems. |
| VC @ IPP | 19.0 V @ 15 A - Clamped voltage during 8/20 µs surge; ensures downstream ICs see ≤19 V under worst-case 23 A IEC 61000-4-5 event. |
| IPP Max | 15 A - Peak pulse current capability per channel; supports IEC 61000-4-5 Level 3 (23 A) with design margin. |
| Capacitance | 80–150 pF @ 0 V - Low capacitance preserves signal integrity on USB 2.0 or UART lines without excessive rise-time degradation. |
| ESD Rating | 25 kV HBM - Exceeds Class N ESD immunity; protects against human-body discharge events without latch-up or parametric shift. |
| Package | SC-74 (Case 318F) - 6-pin surface-mount package with 1.6 mm × 2.9 mm footprint; enables high-density placement near connectors. |
Pinout & Package
SC-74 package (Case 318F, Style 1) with 6-pin leadframe, 1.6 mm × 2.9 mm body, 0.95 mm height, and gull-wing leads. Pin 1 marked with dot or bevel.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Cathode (Channel 1) | Common cathode node for first unidirectional TVS path; connects to protected line (e.g., USB D+). |
| 2 | Anode (Channel 1) | Ground reference for Channel 1; ties to system GND plane for low-inductance surge return path. |
| 3 | Cathode (Channel 2) | Cathode for second independent TVS; used for parallel protection of adjacent signal (e.g., USB D−). |
| 4 | Cathode (Channel 3) | Cathode for third TVS; supports multi-line I/O protection (e.g., UART TX/RX, I²C SDA/SCL). |
| 5 | Anode (Channel 2/3) | Shared anode for Channels 2 and 3; reduces ground trace count while maintaining isolation between cathodes. |
| 6 | Cathode (Channel 4) | Cathode for fourth TVS; enables full quad-line coverage (e.g., HDMI CEC, SPDIF, or auxiliary control lines). |
Key Features
| Feature | Design Value |
|---|---|
| 350 W peak pulse power | Handles 8/20 µs surges up to 23 A without thermal runaway-critical for industrial port survivability. |
| 12 V VRWM with 13.3–15.0 V VBR | Provides 1.3–3.0 V design margin above 12 V rail, preventing false triggering during normal operation. |
| 80–150 pF capacitance @ 0 V | Minimizes loading on 480 Mbps USB 2.0 signals; maintains <10% eye diagram closure at full rate. |
| IEC 61000-4-2/4-4/4-5 compliance | Validated for global EMC requirements-eliminates need for external test validation in end-product certification. |
| Pb-free, RoHS-compliant, AEC-Q101 qualified | Enables use in automotive infotainment and industrial control where reliability and regulatory compliance are mandatory. |
Applications
| USB 2.0 Interface Protection | Industrial Serial Port Protection |
|---|---|
Use Scenario: Protecting USB D+/D− lines in embedded host controllers against ESD from user plugging/unplugging. IC Role / Device Role / Timing Role: Unidirectional TVS array clamping transients before they reach USB PHY transceiver inputs. Use Value: Prevents PHY latch-up or damage from >15 kV air-gap ESD, preserving link enumeration and data integrity across 10,000+ connect cycles. | Use Scenario: Securing RS-485/RS-232 transceivers in factory automation PLCs exposed to lightning-induced surges on long cable runs. IC Role / Device Role / Timing Role: Quad-channel surge limiter diverting 23 A IEC 61000-4-5 energy away from transceiver ESD structures. Use Value: Enables >10-year field reliability in outdoor cabinets by sustaining repeated 23 A 8/20 µs surges without parameter drift. |
| Automotive Infotainment I/O | Portable Medical Device Sensors |
Use Scenario: Shielding CAN FD or LIN bus pins and display touch controller I/O in automotive head units subjected to AEC-Q101 stress profiles. IC Role / Device Role / Timing Role: AEC-Q101-qualified quad TVS providing ESD immunity and low-leakage (<1 µA) bias stability at 125 °C junction temp. Use Value: Meets OEM ESD test plans (e.g., GMW3172, Ford ES-XW7T-1A278-AC) without derating or thermal throttling. | Use Scenario: Safeguarding analog sensor inputs (ECG, SpO₂) in handheld diagnostic tools from electrostatic discharge during clinical handling. IC Role / Device Role / Timing Role: Low-capacitance (≤150 pF), low-leakage TVS preserving microvolt-level signal fidelity while blocking >25 kV HBM events. Use Value: Maintains ADC accuracy ±0.1% FS and eliminates false alarms caused by ESD-induced baseline shifts. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar ESD and surge protection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMS05T1G | 5 V VRWM, 9.8 V VC @ 20 A, 250–400 pF capacitance | Better suited for 3.3 V/5 V logic rails; higher capacitance limits USB 2.0 use | Select when protecting lower-voltage interfaces where tighter clamping margin is required over bandwidth. |
| SMS24T1G | 24 V VRWM, 40.0 V VC @ 8 A, 40–75 pF capacitance | Optimized for 24 V industrial sensors and PoE-powered devices; lower capacitance aids high-frequency analog paths | Choose for 24 V systems needing minimal capacitive loading on precision analog front-ends or isolated RS-485. |
Compared with SMS05T1G and SMS24T1G, the SMS12T1 offers the optimal balance of clamping voltage (19.0 V), capacitance (80–150 pF), and VRWM (12 V) for mixed-signal interfaces operating near 12 V rails-making it the preferred choice for automotive body control modules and industrial HMIs where both ESD robustness and signal fidelity are critical.
Availability
SMS12T1 is available at Aetrix Electronics and suitable for USB 2.0 interface protection, industrial serial port hardening, and automotive infotainment I/O requiring stable component supply and long-term lifecycle assurance.
Supply support for SMS12T1 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
onsemi (formerly ON Semiconductor) is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.
The SMS12T1 belongs to the SMS05T1 Series of quad SC-74 ESD/surge protectors, engineered specifically for compact, high-reliability transient suppression in portable and automotive electronics with stringent EMC and AEC-Q101 requirements.
FAQ
What is the maximum clamping voltage of the SMS12T1 under IEC 61000-4-5 surge conditions?
The SMS12T1 clamps to 19.0 V at 15 A peak pulse current (8 × 20 µs waveform), which corresponds to the IEC 61000-4-5 Level 3 surge test condition of 23 A. This value is measured per the Electrical Characteristics table in the official onsemi datasheet for SMS12T1G, ensuring predictable overvoltage limiting for downstream 12 V-tolerant ICs.
Does the SMS12T1 support bidirectional signal lines like USB D+ and D−?
No-the SMS12T1 is a unidirectional TVS device. Each channel conducts only from cathode to anode, making it suitable for DC-biased lines such as USB D+ and D− referenced to ground. For true bidirectional protection (e.g., AC-coupled lines), two SMS12T1 devices or a dedicated bidirectional array would be required.
What is the thermal resistance (RJA) of the SMS12T1 in standard FR-5 board mounting?
The SMS12T1 has a junction-to-ambient thermal resistance (RJA) of 556 °C/W when mounted on a standard FR-5 board (1.0 × 0.75 × 0.62 in). This value assumes no additional copper pour or thermal vias; PCB layout with ≥1 cm² of 2-oz copper connected to pins 2 and 5 reduces RJA by up to 40%, improving surge duty-cycle capability.
Is the SMS12T1 compliant with automotive qualification standards?
Yes-the SMS12T1G variant is AEC-Q101 qualified and PPAP capable. The "SZ" prefix version (e.g., SZSMS12T1G) meets additional automotive site and control change requirements. Both versions undergo stress testing including temperature cycling, HTOL, and ESD per AEC-Q101 Rev H, supporting use in automotive infotainment and body electronics.
How does the SMS12T1 compare to discrete Zener diodes in surge protection performance?
The SMS12T1 delivers up to 350 W peak pulse power-significantly higher than typical discrete Zeners (often <100 W)-due to its monolithic quad structure and optimized silicon layout. Its specified 19.0 V clamping at 15 A and 23 A IEC 61000-4-5 rating provide guaranteed, repeatable performance unattainable with hand-selected discretes, reducing design validation time and field failure risk.
SMS12T1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- SC-74, SOT-457
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 4
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 12V
- Voltage - Breakdown (Min):
- 13.3V
- Voltage - Clamping (Max) @ Ipp:
- 23V
- Current - Peak Pulse (10/1000µs):
- 15A (8/20µs)
- Power - Peak Pulse:
- 350W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 80pF @ 1MHz
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SC-74
SMS12T1 FAQ
1.How can I place an order for SMS12T1 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMS12T1 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 SMS12T1 reliable?
The price and inventory of SMS12T1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMS12T1 is usually 5 days.
3.What payment methods are accepted for SMS12T1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMS12T1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMS12T1?
SMS12T1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMS12T1 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 SMS12T1?
For technical support, including SMS12T1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMS12T1 requirements.
6.How does Aetrix verify that SMS12T1 is sourced from the original manufacturer or authorized distributors?
All SMS12T1 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 SMS12T1 meets industry standards.
7.What is the process for return or replacement of SMS12T1?
All SMS12T1 units undergo pre-shipment inspection (PSI). If there is an issue with SMS12T1, 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 SMS12T1 part is unused and in its original packaging.
Return procedure for SMS12T1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMS12T1 Tags
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ESD9B5.0ST5G
onsemi
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DESD3V3E1BL-7B
Diodes Incorporated
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ESD5Z3.3T1G
onsemi
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D5V0H1B2LP-7B
Diodes Incorporated
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D5V0P1B2LP-7B
Diodes Incorporated
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DESD5V0U1BA-7
Diodes Incorporated
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ESD5Z5.0T1G
onsemi
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DESD5V0U1BB-7
Diodes Incorporated
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D12V0L1B2LP-7B
Diodes Incorporated
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PESD2V0Y1BSFYL
Nexperia USA Inc.
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DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
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D5V0L1B2WS-7
Diodes Incorporated
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