Semtech Corporation SC2618SKTRT

Overview

SC2618SKTRT from Semtech is a Transient Diverting Suppressor (TDS) 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, 20mΩ dynamic resistance, and 175pF junction capacitance. It protects USB PD, USB Type-C VBus, and load switch inputs in industrial and portable electronics.

For engineers reviewing the SC2618SKTRT datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, DFN-6 package layout guidance, real-world clamping stability across temperature and current, and direct alternatives for 22V bus protection design.

Technical Context

The SC2618SKTRT uses a surge-rated FET as its primary protection element, activated by a precision trigger circuit that senses overvoltage events and rapidly shunts transient current to ground. Unlike conventional TVS diodes, its clamping voltage remains nearly constant - 27.5–28V - across 24A to 40A peak pulse currents and from −40°C to +125°C.

This behavior stems from the FET's decreasing R_DS(on) under surge conditions, yielding ultra-low dynamic resistance (20mΩ) and eliminating the linear VC = V_BR + I_PP × R_DYN dependency seen in pn-junction TVS devices. The device is rated for 1120W peak pulse power and meets IEC 61000-4-4 (±4kV EFT) and IEC 61000-4-5 (±1kV unsymmetrical surge).

Key Specifications

Pinout & Package

SC2618SKTRT is housed in a RoHS-compliant, halogen-free DFN package measuring 1.6mm × 1.6mm × 0.55mm with exposed thermal pad (no internal thermal pad required; energy dissipated in silicon). All six leads are soldered directly to PCB copper for optimal surge current handling.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TDS2211P.C (identical performance, same footprint) and uClamp2411ZA (lower current, higher clamping, different use case), SC2618SKTRT delivers validated 40A/28V capability in production-grade DFN-6 packaging - making it the preferred choice for 22V bus-level surge and ESD protection where clamping stability and energy handling are critical.

Availability

SC2618SKTRT is available at Aetrix Electronics and suitable for USB Type-C power delivery systems, industrial load switch inputs, and notebook/tablet VBus protection requiring stable component supply, full compliance documentation, and long-term lifecycle support.

Supply support for SC2618SKTRT 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, sensing, and connectivity.

The TDS family - including SC2618SKTRT - was engineered specifically to replace conventional TVS diodes in high-voltage, high-energy EOS applications where clamping voltage stability across temperature and current is essential for system reliability.

FAQ

What is the maximum continuous operating voltage for SC2618SKTRT?

The SC2618SKTRT has a reverse stand-off voltage (V_RWM) of 22V, meaning it can safely operate continuously at up to 22V DC or RMS on the protected line without significant leakage or conduction. This makes SC2618SKTRT ideal for USB PD VBus lines and other 22V-rated power rails where sustained voltage tolerance is required.

Does SC2618SKTRT require a thermal pad on the PCB?

No, SC2618SKTRT does not require an external thermal pad. Its DFN-6 package dissipates surge energy directly through the silicon die and into the PCB copper via pins 1–3 (GND) and pins 4–6 (IN), with no internal thermal slug. Layout best practice is to connect all GND pins to a solid ground plane using multiple vias - not a thermal pad - to minimize inductance during 40A transients.

How does SC2618SKTRT differ from standard TVS diodes in clamping behavior?

Unlike standard TVS diodes - whose clamping voltage rises linearly with peak pulse current (VC = V_BR + I_PP × R_DYN) - SC2618SKTRT maintains a nearly constant 27.5–28V clamping voltage from 24A to 40A and across −40°C to +125°C. This is achieved via a surge-rated FET shunt architecture with 20mΩ dynamic resistance, delivering superior protection predictability in thermally demanding applications.

Can SC2618SKTRT be used on high-speed data lines like USB SuperSpeed?

No, SC2618SKTRT is not suitable for USB SuperSpeed (TX/RX), DisplayPort, or HDMI data lines. Its 175pF junction capacitance would severely degrade signal integrity. SC2618SKTRT is intended exclusively for power or low-frequency I/O lines (e.g., VBus, CC, SBU, or load switch inputs); for data lines, Semtech recommends low-capacitance devices like RClamp3371ZC (<0.25pF).

What is the recommended PCB layout for optimal surge performance of SC2618SKTRT?

Place SC2618SKTRT as close as possible to the connector or entry point of the protected line. Connect pins 4–6 (IN) with a single short, wide trace to the protected bus, and tie pins 1–3 (GND) directly to a solid ground plane using ≥3 vias each. Avoid stubs or splits in GND traces - this layout minimizes parasitic inductance and ensures full 40A surge current handling capability as validated in Semtech's application notes.