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Semtech Corporation SC668ULTRT
- Part No.:
- SC668ULTRT
- Manufacturer:
- Semtech Corporation
- Category:
- LED Drivers
- Package:
- 20-VFQFN Exposed Pad
- Datasheet:
-
SC668ULTRT.pdf
- Description:
- IC LED DRVR LIN PWM 25MA 20MLPQ
- Quantity:
- Payment:
- Shipping:
Inventory:1,665
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Product details
Overview
SC668ULTRT 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), and stable 27.5–28V clamping across temperature and current range. It protects USB Type-C power delivery buses, load switch inputs, and industrial interfaces where low, flat clamping voltage is critical to avoid controller damage.
For engineers reviewing the SC668ULTRT datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, DFN-6 package layout guidance, real-world USB PD and load switch protection use cases, and two validated alternative parts with documented functional trade-offs.
Technical Context
The SC668ULTRT 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 - ~27.6V at 40A and stable from –40°C to +125°C - due to decreasing RDS(on) under surge conditions.
It operates with reverse stand-off voltage of 22V, dynamic resistance of 20mΩ (8/20μs), and junction capacitance of 175pF at 22V/1MHz. The device requires all three input pins (4–6) and all three ground pins (1–3) to be connected in parallel to achieve rated 40A surge capability and minimize parasitic inductance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Working Voltage | 22V - defines maximum continuous DC bus voltage it can protect without leakage or conduction. |
| Clamping Voltage | 27.5–28V at 40A (8/20μs) - ensures protected ICs (e.g., USB PD controllers) remain below absolute maximum ratings during surge. |
| Peak Pulse Current | 40A (8/20μs) - meets IEC 61000-4-5 Level 4 industrial surge immunity requirements. |
| ESD Withstand | ±30kV contact & air (IEC 61000-4-2) - exceeds smartphone/tablet ESD robustness requirements. |
| Junction Capacitance | 175pF at 22V/1MHz - low enough for 20V power rail protection without signal integrity impact. |
| Dynamic Resistance | 20mΩ - enables flat clamping by minimizing IR drop increase under rising surge current. |
| Operating Temp | –40°C to +125°C - supports industrial and automotive under-hood environments. |
Pinout & Package
SC668ULTRT is housed in a RoHS-compliant, halogen-free DFN package measuring 1.6mm × 1.6mm × 0.55mm with exposed thermal pad (no solder mask defined). All six terminals are surface-mount; no leaded variant exists. Pin 1 is marked by laser dot.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 3 | GND | Common ground return path - all three must be connected to minimize inductance and enable full 40A rating. |
| 4, 5, 6 | IN | Protected line input - tied together externally to connect to VBUS, load switch input, or USB PD power rail. |
Key Features
| Feature | Design Value |
|---|---|
| Constant clamping voltage | 27.5–28V across 24–40A and –40°C to +125°C - eliminates derating uncertainty vs. TVS diodes. |
| FET-based shunt architecture | Surge-rated MOSFET + precision trigger - achieves <0.1Ω effective RDS(on) during clamping. |
| Low dynamic resistance | 20mΩ - reduces voltage overshoot during fast-rising transients (e.g., ESD). |
| High-energy surge handling | 1120W peak pulse power (8/20μs) - sustains multi-event surge stress in industrial equipment. |
| Small-footprint DFN | 1.6mm × 1.6mm - saves >50% board area vs. SOT-23 or SOIC TVS solutions with comparable ratings. |
Applications
| USB Type-C Power Delivery Protection | Load Switch Input Protection |
|---|---|
|
Use Scenario: Protecting 20V USB PD power bus against lightning-induced surges and connector hot-plug ESD events. IC Role / Device Role / Timing Role: Primary EOS shunt suppressor placed between VBUS and GND, upstream of PD controller and load switch. Use Value: Maintains clamping at ≤28V across temperature - prevents overvoltage damage to 30V-rated PD controllers even at 125°C ambient. |
Use Scenario: Shielding HS2950P-type load switches from EOS during field deployment in remote meters or robotics. IC Role / Device Role / Timing Role: Front-end transient clamp on VIN pin, limiting voltage seen by internal FET gate oxide and current-sense circuitry. Use Value: Clamps at 27.6V @ 40A - stays below 32V absolute max rating of typical industrial load switches, avoiding latch-up or permanent failure. |
| Industrial 24V Rail Protection | Tablet/Notebook DC Power Input Protection |
|
Use Scenario: Safeguarding 22V nominal industrial control rails (e.g., PLC I/O modules) against 1kV/42Ω combo-wave surges per IEC 61000-4-5. IC Role / Device Role / Timing Role: Standalone transient suppressor on main DC input, replacing bulkier bidirectional TVS arrays. Use Value: Delivers 40A surge current capacity in 1.6mm² footprint - enables compact, fanless enclosure designs without thermal derating penalties. |
Use Scenario: Securing 20V DC input of premium tablets against accidental 48V adapter misconnection or ESD during charging port insertion. IC Role / Device Role / Timing Role: First-line defense on power entry, coordinated with downstream e-fuse and OVP circuitry. Use Value: 175pF capacitance avoids power rail instability; ±30kV ESD rating exceeds IEC 61000-4-2 Level 4 - ensures reliability in consumer handling environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TDS2211P.C | Identical electrical specs, same DFN-6 package, identical marking "T22" - direct Semtech replacement with same date-code format. | No functional difference; used interchangeably in USB PD and industrial designs per Semtech's ordering documentation. | Select when sourcing from authorized Semtech channels requiring exact factory traceability and tape-and-reel compliance (3,000 pcs/reel). |
| SMAJ22A | Standard unidirectional TVS diode; 22V VRWM, 35.5V VC @ 22.5A - higher clamping, no flat-voltage behavior, 10× higher dynamic resistance (~200mΩ). | Requires larger PCB area (SMA package), derates significantly above 85°C, unsuitable for tight-clamp USB PD designs. | Choose only for cost-sensitive, non-temperature-critical 22V rail protection where 35.5V clamping is acceptable. |
Compared with SC668ULTRT, TDS2211P.C offers identical performance and form factor with full manufacturer traceability, while SMAJ22A provides lower-cost surge suppression at the expense of clamping voltage stability, temperature resilience, and board space efficiency.
Availability
SC668ULTRT is available at Aetrix Electronics and suitable for USB Type-C power delivery systems, industrial 22V rail protection, and load switch front-end safeguarding requiring stable component supply, long-term lifecycle support, and guaranteed RoHS/halogen-free compliance.
Supply support for SC668ULTRT 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.
The SC668ULTRT belongs to Semtech's Transient Diverting Suppressor (TDS) family, engineered to replace conventional TVS diodes in high-reliability 20–24V power rail applications demanding flat clamping, wide temperature operation, and minimal board footprint.
FAQ
What is the exact package type and dimensions of SC668ULTRT?
SC668ULTRT uses a 6-pin DFN package measuring 1.6mm × 1.6mm × 0.55mm with exposed thermal pad. Pin pitch is 0.5mm; pin 1 is marked by a laser dot. This matches Semtech's standardized DFN outline for TDS devices and requires no thermal pad soldering per datasheet layout guidelines.
Does SC668ULTRT require external bias or control signals to operate?
No, SC668ULTRT is fully passive and self-triggering. It contains an integrated precision trigger circuit and surge-rated FET - no external voltage, resistor, or enable signal is needed. It activates automatically when transient voltage exceeds its 25–27.9V breakdown threshold, making SC668ULTRT ideal for simple, reliable front-end protection.
How does SC668ULTRT's clamping voltage compare to standard TVS diodes at high temperature?
At 125°C, SC668ULTRT maintains clamping at ~27.6V @ 40A, whereas a typical 22V TVS diode (e.g., SMAJ22A) clamps at ~38V under identical conditions. This 10.4V margin directly enables robust USB PD controller protection at elevated ambient temperatures where SC668ULTRT remains within safe operating limits.
Can SC668ULTRT be used on data lines like USB SuperSpeed or DisplayPort?
No - SC668ULTRT is optimized for power rail and high-current I/O protection with 175pF capacitance, which would distort high-speed signals. For USB SS, DP, or HDMI lines, Semtech recommends low-capacitance TVS devices like RClamp3371ZC (<0.25pF); SC668ULTRT should only be applied to VBUS, CC/SBU, or load switch VIN paths.
Is SC668ULTRT compliant with automotive AEC-Q200 or industrial safety standards?
SC668ULTRT is not AEC-Q200 qualified, but it meets IEC 61000-4-2 (ESD), IEC 61000-4-4 (EFT), and IEC 61000-4-5 (surge) for industrial environments. Its –40°C to +125°C operating range and UL 94V-0 molding compound support harsh industrial use, though automotive qualification requires separate validation beyond SC668ULTRT's published scope.
SC668ULTRT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Semtech Corporation
- Series:
- -
- Package/Case:
- 20-VFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Linear
- Topology:
- -
- Internal Switch(s):
- Yes
- Number of Outputs:
- 8 + 4LDOs
- Voltage - Supply (Min):
- 2.9V
- Voltage - Supply (Max):
- 5.5V
- Voltage - Output:
- -
- Current - Output / Channel:
- 25mA
- Frequency:
- 400kHz
- Dimming:
- PWM
- Applications:
- Backlight
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-MLPQ-UT (3x3)
SC668ULTRT FAQ
1.How can I place an order for SC668ULTRT through Aetrix?
Please submit a Request for Quotation (RFQ) for SC668ULTRT 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 SC668ULTRT reliable?
The price and inventory of SC668ULTRT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SC668ULTRT is usually 5 days.
3.What payment methods are accepted for SC668ULTRT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SC668ULTRT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SC668ULTRT?
SC668ULTRT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SC668ULTRT 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 SC668ULTRT?
For technical support, including SC668ULTRT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SC668ULTRT requirements.
6.How does Aetrix verify that SC668ULTRT is sourced from the original manufacturer or authorized distributors?
All SC668ULTRT 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 SC668ULTRT meets industry standards.
7.What is the process for return or replacement of SC668ULTRT?
All SC668ULTRT units undergo pre-shipment inspection (PSI). If there is an issue with SC668ULTRT, 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 SC668ULTRT part is unused and in its original packaging.
Return procedure for SC668ULTRT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SC668ULTRT Tags
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