Semtech Corporation SC2440ATETRT

Overview

SC2440ATETRT from Semtech is a Transient Diverting Suppressor (TDS) designed for high-energy EOS protection of 22V-rated power or I/O lines. It delivers ±30kV IEC 61000-4-2 ESD immunity, 40A peak pulse current (8/20μs), and stable 27.5–28V clamping across temperature and current range - enabling robust USB Type-C PD and load switch input protection in industrial and portable electronics.

For engineers reviewing the SC2440ATETRT datasheet, pinout, applications, or equivalent options, key selection criteria include its constant-clamp FET architecture, DFN 1.6×1.6mm 6-lead package, 22V working voltage, 175pF junction capacitance, and dynamic resistance of 20mΩ - all critical for low-voltage-margin, high-reliability surge protection designs.

Technical Context

The SC2440ATETRT uses a surge-rated MOSFET as its primary protection element, activated by a precision trigger circuit that senses overvoltage events above ~27.9V breakdown. Unlike conventional TVS diodes, its clamping voltage remains nearly flat (27.5–28V) from 24A to 40A IPP due to decreasing R_DS(on) under surge conditions.

It operates across –40°C to +125°C with <600nA reverse leakage at 22V, 175pF capacitance at 22V/1MHz, and 1120W peak pulse power handling. The device protects one line with three parallel input pins (4–6) and three ground pins (1–3), requiring full pin connection for rated 40A performance.

Key Specifications

Pinout & Package

SC2440ATETRT is housed in a RoHS-compliant, halogen-free DFN 1.6mm × 1.6mm × 0.55mm 6-lead package with exposed thermal pad not required (energy dissipated in silicon). All six pins must be soldered: pins 1–3 are tied internally to GND; pins 4–6 are tied internally to the protected line input.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TDS2211P (identical device) and uClamp2411ZA (lower IPP, higher V_C, non-flat clamp), SC2440ATETRT offers guaranteed 40A surge handling with 27.5V clamping across –40°C to +125°C - making it the sole choice for 22V power rail protection where thermal derating and voltage margin are critical.

Availability

SC2440ATETRT is available at Aetrix Electronics and suitable for USB Type-C PD systems, industrial load switch inputs, and IoT power rail protection requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for SC2440ATETRT 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.

SC2440ATETRT belongs to Semtech's Transient Diverting Suppressor (TDS) product line, engineered to replace conventional TVS diodes in high-reliability 20–30V power rail protection applications demanding flat clamping and temperature stability.

FAQ

What is the exact function of SC2440ATETRT in a circuit?

SC2440ATETRT functions as a transient diverting suppressor that actively shunts high-energy EOS events (ESD, lightning surges) to ground using an integrated surge-rated FET. Unlike passive TVS diodes, it maintains a near-constant 27.5–28V clamping voltage across 24–40A surge currents and –40°C to +125°C - protecting downstream 22V-rated ICs such as USB PD controllers and load switches. The SC2440ATETRT achieves this via a precision trigger circuit that turns on the FET when voltage exceeds ~27.9V.

Is SC2440ATETRT pin-compatible with standard TVS diodes like SMAJ22A?

No, SC2440ATETRT is not pin-compatible with SMAJ22A or other 2-pin TVS diodes. It uses a 6-pin DFN package with three dedicated input pins (4–6) and three ground pins (1–3) to handle 40A surge current with minimal inductance. SMAJ22A is a 2-pin DO-214AC device with different thermal and layout requirements. Replacing SMAJ22A with SC2440ATETRT requires PCB redesign to accommodate the 1.6×1.6mm footprint and symmetric 3×IN/3×GND routing - but delivers superior clamping stability and surge capability.

Does SC2440ATETRT require a thermal pad or heatsink?

No, SC2440ATETRT does not require a thermal pad or external heatsink. Its FET-based architecture dissipates surge energy in the silicon channel rather than at a PN junction, and the DFN package is designed for direct PCB copper conduction. The datasheet explicitly states "no thermal pad is needed" - instead, designers must connect all three GND pins (1–3) to a solid ground plane using multiple vias to minimize parasitic inductance, which is more critical than thermal mass for effective 40A surge handling.

Can SC2440ATETRT protect high-speed data lines like USB SS or PCIe?

No, SC2440ATETRT is not intended for high-speed data line protection. With 175pF junction capacitance, it is optimized for 22V power rails or low-frequency I/O lines (e.g., USB CC, SBU, or load switch enable inputs). For SuperSpeed USB (5–10Gbps) or PCIe lanes, Semtech recommends ultra-low-capacitance devices like RClamp3371ZC (<0.25pF). Using SC2440ATETRT on data lines would severely degrade signal integrity due to excessive capacitive loading and bandwidth limitation.

What is the marking code and packaging format for SC2440ATETRT?

SC2440ATETRT is marked with "T22" followed by a two-digit date code (e.g., T2223 for 2023) and a dot indicating Pin 1 location. It ships in tape-and-reel format with 3,000 units per 7-inch reel, consistent with Semtech's standard packaging for DFN devices. The part is Pb-free, halogen-free, and RoHS/WEEE compliant, with UL 94V-0 molding compound - matching the specifications of the TDS2211P variant it represents.