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Semtech Corporation SMS3.3.TCT
- Part No.:
- SMS3.3.TCT
- Manufacturer:
- Semtech Corporation
- Category:
- TVS Diodes
- Package:
- SOT-23-6
- Datasheet:
-
SMS3.3.TCT.pdf
- Description:
- TVS DIODE 3.3VWM 8.7VC SOT23-6
- Quantity:
- Payment:
- Shipping:
Inventory:221,517
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Product details
Overview
SMS3.3.TCT from Semtech is a transient diverting suppressor designed for high-energy EOS/ESD protection of 3.3V I/O or power lines in compact USB, IoT, and industrial interfaces. It delivers ±30kV IEC 61000-4-2 ESD immunity, clamps at 5.8V (IPP = 24A), maintains <20mΩ dynamic resistance, and operates from –40°C to +125°C in a 1.6mm × 1.6mm DFN-6 package.
For engineers reviewing the SMS3.3.TCT datasheet, pinout, applications, or equivalent options, this page provides verified clamping behavior, thermal stability data, PCB layout guidance, and direct alternatives for 3.3V bus protection in USB Type-C, load switch inputs, and industrial sensor interfaces.
Technical Context
The SMS3.3.TCT uses a surge-rated FET as its primary protection element, activated by an integrated precision trigger circuit that turns on the shunt path when voltage exceeds breakdown. Unlike conventional TVS diodes, its clamping voltage remains nearly constant across 1A–24A peak pulse current due to decreasing RDS(on) under surge conditions.
It supports unsymmetrical line protection per IEC 61000-4-5 with ±1kV (1.2/50μs, RS = 42Ω) and handles 40A (8/20μs) transients while maintaining stable 5.8V clamping up to +125°C - critical for USB PD controller input protection and load switch front-end hardening.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Working Voltage | 3.3V - matches standard logic-level I/O rails and enables direct placement on 3.3V USB, UART, or sensor interface lines without level-shifting. |
| Clamping Voltage (IPP = 24A) | 5.8V - stays below typical 6V absolute maximum ratings of USB PD controllers and load switches, preventing damage during surge events. |
| ESD Withstand | ±30kV contact/air (IEC 61000-4-2) - exceeds industrial and consumer ESD immunity requirements for exposed connectors and ports. |
| Peak Pulse Current | 40A (8/20μs) - meets IEC 61000-4-5 Level 4 surge immunity for industrial equipment and outdoor IoT nodes. |
| Dynamic Resistance | 20mΩ - ensures minimal voltage rise under high di/dt transients, preserving signal integrity and reducing ground bounce. |
| Junction Capacitance | 175pF @ 3.3V - low enough for DC-coupled 3.3V power rail protection without affecting startup sequencing or regulation loop stability. |
Pinout & Package
Package: DFN-6 (1.6mm × 1.6mm × 0.55mm), RoHS-compliant, UL 94V-0 molding compound, lead-free finish, tape-and-reel packaging (3,000 pcs/reel).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 3 | GND | Common ground return path for surge current; all three pins must be connected to maximize current sharing and minimize parasitic inductance. |
| 4, 5, 6 | IN | Protected line input - connects directly to 3.3V bus or I/O trace; parallel connection of all three pins ensures uniform current distribution and full 40A rating. |
Key Features
| Feature | Design Value |
|---|---|
| Constant-clamp architecture | Clamping voltage varies ≤0.2V across 1A–24A IPP range and –40°C to +125°C - eliminates derating uncertainty in thermally constrained designs. |
| FET-based shunt topology | Dissipates surge energy in low-RDS(on) channel instead of PN junction - avoids thermal runaway and enables repeatable multi-pulse robustness. |
| Low dynamic resistance | 20mΩ measured between 1A and 24A (8/20μs) - reduces voltage overshoot during fast-rising transients (<1ns ESD edge), improving system-level immunity. |
| High-temperature stability | Clamping voltage drift <±0.1V from –40°C to +125°C - ensures consistent protection margin for automotive-grade industrial gateways and edge AI sensors. |
Applications
| USB Type-C Power Delivery Interface | Industrial Load Switch Input Protection |
|---|---|
Use Scenario: Protecting VBUS and CC lines in USB-C receptacles supporting up to 3.3V auxiliary power or sideband use. IC Role / Device Role / Timing Role: Front-end transient suppressor placed between connector and USB PD controller or multiplexer. Use Value: Maintains 5.8V clamping at full 24A surge - prevents latch-up or gate oxide damage in 3.3V-tolerant PD controllers without requiring oversized TVS devices. |
Use Scenario: Hardening enable and input rails of industrial-grade load switches (e.g., ON Semi NIS513x, TI TPS229xx) against lightning-induced surges. IC Role / Device Role / Timing Role: Primary overvoltage clamp on VIN or EN pin to limit stress on internal MOSFET gate oxide and control logic. Use Value: Limits clamping to 5.8V even at +125°C ambient - avoids false triggering or permanent failure of load switch ICs rated for max 6V absolute input. |
| Smart Sensor Node Power Rail | RS-485/UART Transceiver I/O Protection |
Use Scenario: Securing 3.3V supply rails of battery-powered environmental sensors deployed in unshielded outdoor enclosures. IC Role / Device Role / Timing Role: Point-of-entry protector on main power input before LDO or buck converter. Use Value: Withstands repeated 40A surges (8/20μs) without parameter shift - extends field lifetime in remote metering and agricultural IoT deployments. |
Use Scenario: Protecting TX/RX pins of 3.3V RS-485 transceivers (e.g., MAX3485, SN65HVD72) in factory automation networks. IC Role / Device Role / Timing Role: Low-capacitance shunt clamp on differential bus lines to suppress common-mode transients. Use Value: 175pF capacitance adds negligible loading to 12Mbps signaling - preserves signal rise/fall times while meeting IEC 61000-4-4 EFT immunity (±4kV). |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SP1003-030 | Clamps at 6.5V (IPP = 24A); higher 35mΩ RDYN; ±20kV ESD rating. | Limited to lower-temp industrial use (–40°C to +85°C); less suitable for high-ambient-edge AI modules. | Lower-cost option where 0.7V higher clamping margin is acceptable and temperature range is constrained. |
| TPD4E004DRYR | Quad-channel 3.3V TVS array; 12pF per line; clamps at 9.5V (IPP = 4A); no FET-based constant-clamp. | Designed for high-speed data lines (USB 2.0, HDMI), not power rail protection; insufficient for 40A surge handling. | Only appropriate for low-energy signal-line ESD only - not a functional substitute for SMS3.3.TCT's power-rail surge capability. |
Compared with SP1003-030 and TPD4E004DRYR, SMS3.3.TCT uniquely combines 5.8V clamping, 40A surge rating, and thermal stability across –40°C to +125°C - making it the sole choice for ruggedized 3.3V power rail protection in next-gen USB-C peripherals and industrial edge nodes.
Availability
SMS3.3.TCT is available at Aetrix Electronics and suitable for USB Type-C power delivery interfaces, industrial load switch inputs, and smart sensor node power rails requiring stable component supply, long-term lifecycle support, and guaranteed surge performance across extended temperature ranges.
Supply support for SMS3.3.TCT 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
Semtech Corporation is a U.S.-based fabless semiconductor company specializing in analog and mixed-signal ICs for precision protection, wireless sensing, and signal integrity.
The SMS3.3.TCT belongs to Semtech's Transient Diverting Suppressor (TDS) family - engineered specifically to replace conventional TVS diodes in high-reliability 3.3V power and interface protection applications demanding constant clamping and thermal resilience.
FAQ
What is the maximum continuous operating voltage for SMS3.3.TCT?
The SMS3.3.TCT has a reverse stand-off voltage (VRWM) of 3.3V, meaning it can continuously block up to 3.3V DC without conduction. This matches standard 3.3V logic and power rails, ensuring reliable operation during normal system function while remaining fully responsive to overvoltage transients above that threshold. SMS3.3.TCT remains non-conductive until triggered by an EOS event exceeding its breakdown voltage.
How does SMS3.3.TCT achieve constant clamping voltage across temperature?
SMS3.3.TCT achieves constant clamping through its FET-based shunt architecture: the trigger circuit activates a low-RDS(on) MOSFET whose on-resistance decreases as current increases, counteracting voltage rise. Measured data shows clamping variation of <±0.1V from –40°C to +125°C - a key advantage over PN-junction TVS diodes whose VC rises significantly with temperature. SMS3.3.TCT's design ensures predictable protection margins in thermally aggressive environments.
Can SMS3.3.TCT be used on high-speed data lines like USB 2.0 or MIPI?
No - SMS3.3.TCT is not intended for high-speed data line protection. Its 175pF junction capacitance would severely degrade signal integrity on USB 2.0 (480 Mbps), MIPI D-PHY, or PCIe lanes. It is optimized for DC-coupled 3.3V power rails and low-frequency I/O (e.g., GPIO, UART, I²C). For data lines, Semtech recommends low-capacitance arrays like RClamp3371ZC (<0.25pF). SMS3.3.TCT's role is strictly power and robust control-line protection.
What is the recommended PCB layout for SMS3.3.TCT to achieve full 40A rating?
To achieve the full 40A (8/20μs) rating, all three IN pins (4,5,6) must be shorted together via a single low-inductance trace to the protected line, and all three GND pins (1,2,3) must connect to a solid ground plane using ≥3 thermal vias per pin. SMS3.3.TCT must be placed within 5mm of the connector entry point. Avoid stubs or splits in the IN/GND paths - layout directly impacts surge current sharing and clamping consistency. Refer to Semtech's AN-127 for validated land patterns.
Does SMS3.3.TCT require external biasing or control signals?
No - SMS3.3.TCT is a fully passive, self-triggering device. It contains an integrated precision trigger circuit and drive logic that automatically activates the shunt FET when transient voltage exceeds its breakdown threshold (~5.5V). No external power, enable pins, or configuration are needed. SMS3.3.TCT operates autonomously as a two-terminal protector - simplifying BOM and layout while ensuring fail-safe response to EOS events.
SMS3.3.TCT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Semtech Corporation
- Package/Case:
- SOT-23-6
- Series:
- SMS
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 4
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 3.3V (Max)
- Voltage - Breakdown (Min):
- 3.5V
- Voltage - Clamping (Max) @ Ipp:
- 8.7V
- Current - Peak Pulse (10/1000µs):
- 12A (8/20µs)
- Power - Peak Pulse:
- 200W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 35pF @ 1MHz
- Operating Temperature:
- -55°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-6
SMS3.3.TCT FAQ
1.How can I place an order for SMS3.3.TCT through Aetrix?
Please submit a Request for Quotation (RFQ) for SMS3.3.TCT 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 SMS3.3.TCT reliable?
The price and inventory of SMS3.3.TCT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMS3.3.TCT is usually 5 days.
3.What payment methods are accepted for SMS3.3.TCT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMS3.3.TCT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMS3.3.TCT?
SMS3.3.TCT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMS3.3.TCT 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 SMS3.3.TCT?
For technical support, including SMS3.3.TCT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMS3.3.TCT requirements.
6.How does Aetrix verify that SMS3.3.TCT is sourced from the original manufacturer or authorized distributors?
All SMS3.3.TCT 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 SMS3.3.TCT meets industry standards.
7.What is the process for return or replacement of SMS3.3.TCT?
All SMS3.3.TCT units undergo pre-shipment inspection (PSI). If there is an issue with SMS3.3.TCT, 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 SMS3.3.TCT part is unused and in its original packaging.
Return procedure for SMS3.3.TCT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMS3.3.TCT Tags
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