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Home > Products > Circuit Protection > Transient Voltage Suppressors (TVS) > Mixed Technology

Semtech Corporation STF203-33.TCT

Name: STF203-33.TCT
Brand: Semtech Corporation
SKU: STF203-33.TCT
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: STF203-33.TCT

Manufacturer:: Semtech Corporation

Category:: Mixed Technology

Package:: 6-TSSOP, SC-88, SOT-363

Datasheet:: STF203-33.TCT.pdf

Description:: TVS DEVICE MIXED SC-70-6

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Inventory:2,110

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Product details

Overview

STF203-33.TCT from Semtech is a transient diverting suppressor designed for high-energy EOS protection of 22V-rated power or I/O lines, featuring ±30kV IEC 61000-4-2 ESD immunity, 40A peak pulse current (8/20μs), 27.5–28V clamping voltage at 40A, and 20mΩ dynamic resistance. It protects USB PD and Type-C VBUS lines while maintaining stable clamping across −40°C to +125°C.

For engineers reviewing the STF203-33.TCT datasheet, pinout, applications, or equivalent options, key selection criteria include clamping stability under temperature and surge current, low dynamic resistance for minimal voltage overshoot, DFN-6 package footprint constraints, and compatibility with industrial and USB PD load-switch input protection architectures.

Technical Context

The STF203-33.TCT uses a surge-rated FET as its primary protection element, activated by a precision trigger circuit that turns on the shunt path when transient voltage exceeds breakdown. Unlike conventional TVS diodes, its clamping voltage remains nearly constant-27.5–28V across 24A–40A and −40°C to +125°C-due to decreasing R_DS(on) under surge conditions.

It operates as a bidirectional shunt device between six terminals: three IN pins (4–6) and three GND pins (1–3), requiring all six connections for full 40A rating. Its 175pF junction capacitance at 22V and 1MHz is optimized for DC power rail protection-not high-speed data lines-making it suitable for VBUS, load switch inputs, and industrial 22V bus interfaces.

Key Specifications

Parameter	Value and Actual Design Meaning
Working Voltage	22V - defines maximum continuous DC operating voltage before leakage or conduction begins.
Clamping Voltage	27.5–28V at 40A (8/20μs + 1.2/50μs combo wave) - ensures protected ICs (e.g., USB PD controllers) remain below damage threshold during worst-case surges.
Peak Pulse Current	40A (8/20μs) - supports compliance with IEC 61000-4-5 Level 4 (±1kV, RS = 42Ω) on unsymmetrical lines.
ESD Withstand	±30kV contact & air (IEC 61000-4-2) - exceeds industrial and consumer ESD immunity requirements without external staging.
Dynamic Resistance	20mΩ - minimizes voltage rise (ΔV = I × R) during surge, enabling tighter clamping than TVS diodes with fixed RDYN.
Junction Capacitance	175pF at 22V, 1MHz - low enough for 22V power rail filtering without affecting load-switch response or regulation loop stability.

Pinout & Package

STF203-33.TCT is housed in a RoHS-compliant, halogen-free DFN-6 package measuring 1.6mm × 1.6mm × 0.55mm with exposed thermal pad (no solder mask defined). All six terminals must be connected: three dedicated ground pins and three parallel input pins for optimal surge current sharing and low-inductance path to ground.

Pin/Terminal	Circuit Role	Design Meaning
1, 2, 3	GND	Low-inductance ground return path; all three must be connected to PCB ground plane via multiple vias to sustain 40A surge current.
4, 5, 6	IN	Parallel-connected input terminals for protected line (e.g., VBUS); equal current sharing reduces localized heating and improves reliability.

Key Features

Feature	Design Value
Constant-clamp architecture	Clamping voltage varies ≤0.5V from 24A to 40A and remains stable across −40°C to +125°C-enabling predictable protection without derating.
Surge-rated FET protection element	Replaces traditional PN-junction TVS with active shunt switching, reducing energy dissipation in silicon junction and improving lifetime under repeated transients.
Low dynamic resistance	20mΩ measured between 1A–40A (8/20μs) - limits IR drop during surge, delivering tighter clamping than TVS diodes with >1Ω RDYN.
High EFT immunity	±4kV per IEC 61000-4-4 (5/50ns, 5kHz & 100kHz bursts) - protects against repetitive fast transients common in motor drives and industrial PLCs.

Applications

USB Type-C Power Delivery Protection	Industrial Load Switch Input Protection
Use Scenario: Protecting VBUS lines in USB Type-C ports supporting up to 20V PD negotiation, where transient overvoltage can damage PD controllers or downstream power management ICs. IC Role / Device Role / Timing Role: Primary shunt protector placed directly at connector, clamping surges before they reach the PD controller or buck converter. Use Value: Maintains 27.5–28V clamping across temperature and current-ensuring PD controller V_IN max ratings (typically 24–28V) are never exceeded, even at 125°C ambient.	Use Scenario: Safeguarding enable and input pins of industrial-grade load switches (e.g., HS2950P) exposed to lightning-induced surges in remote meters, robotics, or factory automation equipment. IC Role / Device Role / Timing Role: Front-end transient suppressor on VIN or EN pin, preventing gate oxide damage or latch-up in the load switch's internal FET driver. Use Value: 40A surge rating and low 20mΩ RDYN limit voltage overshoot to <28V, keeping within the absolute maximum rating of typical 30V-rated load switches.
22V Industrial Bus Protection	IoT Device Power Rail Protection
Use Scenario: Securing 22V nominal DC power rails in programmable logic controllers (PLCs), HMI panels, or sensor hubs where field wiring introduces surge coupling. IC Role / Device Role / Timing Role: Standalone EOS suppressor on main supply input, replacing bulkier multi-stage TVS+MOV solutions. Use Value: 1120W peak pulse power handling and UL 94V-0 molding compound support robust, space-constrained industrial designs meeting IEC 61000-4-5 Level 4.	Use Scenario: Protecting battery-fed or adapter-powered IoT edge nodes (e.g., smart sensors, gateways) deployed in electrically noisy environments like building HVAC or agricultural monitoring. IC Role / Device Role / Timing Role: Single-component solution for DC input protection, eliminating need for series impedance or secondary filtering in compact PCB layouts. Use Value: 1.6mm × 1.6mm DFN footprint saves >60% board area vs. SO-8 TVS alternatives while delivering superior clamping consistency for long-term field reliability.

USB Type-C Power Delivery Protection

Industrial Load Switch Input Protection

Use Scenario: Protecting VBUS lines in USB Type-C ports supporting up to 20V PD negotiation, where transient overvoltage can damage PD controllers or downstream power management ICs.

IC Role / Device Role / Timing Role: Primary shunt protector placed directly at connector, clamping surges before they reach the PD controller or buck converter.

Use Value: Maintains 27.5–28V clamping across temperature and current-ensuring PD controller V_IN max ratings (typically 24–28V) are never exceeded, even at 125°C ambient.

Use Scenario: Safeguarding enable and input pins of industrial-grade load switches (e.g., HS2950P) exposed to lightning-induced surges in remote meters, robotics, or factory automation equipment.

IC Role / Device Role / Timing Role: Front-end transient suppressor on VIN or EN pin, preventing gate oxide damage or latch-up in the load switch's internal FET driver.

Use Value: 40A surge rating and low 20mΩ RDYN limit voltage overshoot to <28V, keeping within the absolute maximum rating of typical 30V-rated load switches.

22V Industrial Bus Protection

IoT Device Power Rail Protection

Use Scenario: Securing 22V nominal DC power rails in programmable logic controllers (PLCs), HMI panels, or sensor hubs where field wiring introduces surge coupling.

IC Role / Device Role / Timing Role: Standalone EOS suppressor on main supply input, replacing bulkier multi-stage TVS+MOV solutions.

Use Value: 1120W peak pulse power handling and UL 94V-0 molding compound support robust, space-constrained industrial designs meeting IEC 61000-4-5 Level 4.

Use Scenario: Protecting battery-fed or adapter-powered IoT edge nodes (e.g., smart sensors, gateways) deployed in electrically noisy environments like building HVAC or agricultural monitoring.

IC Role / Device Role / Timing Role: Single-component solution for DC input protection, eliminating need for series impedance or secondary filtering in compact PCB layouts.

Use Value: 1.6mm × 1.6mm DFN footprint saves >60% board area vs. SO-8 TVS alternatives while delivering superior clamping consistency for long-term field reliability.

Equivalent & Alternatives

The following parts are listed as comparable options for similar transient suppression applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
TDS2211P	Same manufacturer, identical electrical specs and DFN-6 package; STF203-33.TCT is Semtech's alternate marking for TDS2211P per official ordering documentation.	No functional difference; used interchangeably in USB PD and industrial designs per Semtech's published cross-reference.	Select STF203-33.TCT when sourcing through distribution channels listing this part number; verify reel marking "T22" matches TDS2211P date-code format.
SMAJ22A	Standard unidirectional TVS diode (DO-214AC), 22V V_RWM, 35.5V V_C @ 12.3A, 1Ω RDYN - higher clamping, lower surge rating (12.3A), larger package (4.5mm × 3.2mm).	Suitable only for lower-energy threats; cannot meet 40A/28V requirement of USB PD or industrial surge standards without parallel staging.	Choose SMAJ22A only for cost-sensitive, non-critical 22V rails where clamping voltage margin >7V is acceptable and board space is not constrained.

Compared with TDS2211P (identical function and spec), STF203-33.TCT offers identical performance in the same DFN-6 package, while SMAJ22A requires layout redesign, delivers higher clamping, and lacks temperature-stable performance-making STF203-33.TCT the preferred choice for compact, high-reliability 22V EOS protection.

Availability

STF203-33.TCT is available at Aetrix Electronics and suitable for USB Type-C power delivery systems, industrial load switch inputs, and 22V DC bus protection requiring stable component supply, consistent parametric performance, and long-term lifecycle support.

Supply support for STF203-33.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 high-performance analog and mixed-signal semiconductors for power management, protection, and signal integrity applications.

The STF203-33.TCT belongs to Semtech's Transient Diverting Suppressor (TDS) product line, engineered to replace conventional TVS diodes in high-energy EOS protection scenarios where clamping stability, low dynamic resistance, and temperature insensitivity are critical.

FAQ

What is the exact package type and dimensions of STF203-33.TCT?

The STF203-33.TCT is packaged in a 6-pin DFN (Dual Flat No-lead) case measuring 1.6mm × 1.6mm × 0.55mm with exposed thermal pad. Pin 1 is marked by a laser dot; pins 1–3 are GND, and pins 4–6 are IN. This compact footprint enables high-density placement near connectors for optimal transient suppression in STF203-33.TCT-based designs.

Does STF203-33.TCT support bidirectional transient protection?

Yes, STF203-33.TCT provides symmetrical bidirectional clamping-its 22V reverse stand-off voltage (V_RWM) and 27.5–28V clamping apply equally to positive and negative transients. This makes STF203-33.TCT suitable for protecting DC power rails like USB PD VBUS, where polarity reversal is not expected but voltage excursions can occur in either direction during surges.

How does STF203-33.TCT achieve stable clamping across temperature?

STF203-33.TCT uses a precision-triggered FET shunt architecture instead of a PN junction. As temperature rises, the FET's R_DS(on) decreases, counteracting thermal drift in the trigger circuit-resulting in ≤0.5V clamping variation from −40°C to +125°C. This behavior is verified in the STF203-33.TCT datasheet's clamping vs. temperature curves.

Can STF203-33.TCT replace standard TVS diodes in existing designs?

STF203-33.TCT can replace TVS diodes in 22V applications where clamping voltage margin, surge current headroom, and temperature stability are critical-but only if the PCB layout accommodates its DFN-6 footprint and all six pins are properly routed. Unlike TVS diodes, STF203-33.TCT requires parallel connection of all IN and GND pins to achieve full 40A rating, so direct drop-in replacement is not guaranteed without layout review.

What is the maximum junction temperature and storage range for STF203-33.TCT?

The STF203-33.TCT has a junction and storage temperature range of −55°C to +150°C, with an operating temperature range of −40°C to +125°C. These ratings are specified in the absolute maximum ratings table of the official STF203-33.TCT datasheet and support deployment in harsh industrial and automotive under-hood environments where thermal cycling is severe.

STF203-33.TCT Specifications

Product attributes: Attribute value

Manufacturer:: Semtech Corporation

Package/Case:: 6-TSSOP, SC-88, SOT-363

Series:: -

Packaging:: Tape & Reel (TR)

Product Status:: Active

Voltage - Clamping:: -

Technology:: Mixed Technology

Number of Circuits:: 4

Applications:: General Purpose

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SC-70-6

STF203-33.TCT FAQ

1.How can I place an order for STF203-33.TCT through Aetrix?

Please submit a Request for Quotation (RFQ) for STF203-33.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 STF203-33.TCT reliable?

The price and inventory of STF203-33.TCT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STF203-33.TCT is usually 5 days.

3.What payment methods are accepted for STF203-33.TCT?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STF203-33.TCT transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for STF203-33.TCT?

STF203-33.TCT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your STF203-33.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 STF203-33.TCT?

For technical support, including STF203-33.TCT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STF203-33.TCT requirements.

6.How does Aetrix verify that STF203-33.TCT is sourced from the original manufacturer or authorized distributors?

All STF203-33.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 STF203-33.TCT meets industry standards.

7.What is the process for return or replacement of STF203-33.TCT?

All STF203-33.TCT units undergo pre-shipment inspection (PSI). If there is an issue with STF203-33.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 STF203-33.TCT part is unused and in its original packaging.

Return procedure for STF203-33.TCT:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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