Semtech Corporation 3SM2

Overview

TDS2211P from Semtech is a transient diverting suppressor designed to protect single 22V I/O or power lines against high-energy EOS events including ±30kV ESD (IEC 61000-4-2), 40A surge (8/20μs), and ±4kV EFT (IEC 61000-4-4); it uses a surge-rated FET with 20mΩ dynamic resistance and maintains stable 27.5–28V clamping across 24–40A and −40°C to +125°C for USB PD, Type-C, and industrial load switch inputs.

For engineers reviewing the TDS2211P datasheet, pinout, applications, or equivalent options, key selection criteria include clamping voltage stability over current/temperature, 175pF junction capacitance at 22V, DFN 1.6×1.6mm 6-lead package layout requirements, and its FET-based shunt architecture versus conventional TVS diodes.

Technical Context

The TDS2211P implements a precision-triggered shunt FET architecture: a dedicated trigger circuit senses overvoltage and activates a low-R_DS(on) FET to divert transients directly to ground. Unlike TVS diodes whose clamping rises linearly with peak pulse current (V_C = V_BR + I_PP × R_DYN), the TDS2211P achieves near-constant clamping (27.5–28V) due to decreasing FET on-resistance as current increases.

This architecture delivers superior thermal stability - clamping remains flat from −40°C to +125°C - and enables reliable protection of sensitive 22V-bus interfaces such as USB PD controllers and load switch inputs where conventional TVS devices exceed damage thresholds at elevated temperatures or high I_PP.

Key Specifications

Pinout & Package

Package: DFN 1.6 mm × 1.6 mm × 0.55 mm, 6-lead, Pb-free, RoHS-compliant, UL 94V-0 molding compound, marked "T22" + date code.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ22A and SP1003-220K, the TDS2211P delivers significantly lower and thermally stable clamping (27.5–28V vs. ≥35.5V), full 40A surge capability, and FET-based architecture enabling consistent protection across temperature and current - making it uniquely suited for 22V USB PD and industrial power rail applications where reliability margins are critical.

Availability

TDS2211P is available at Aetrix Electronics and suitable for USB Type-C implementations, industrial load switch designs, and IoT device power rail protection requiring stable component supply and long-term lifecycle support.

Supply support for TDS2211P 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 TDS series is Semtech's proprietary transient diverting suppressor product line, engineered to replace conventional TVS diodes in high-reliability 22V–36V power and interface protection applications using active FET-shunt technology.

FAQ

What is the primary protection mechanism used in the TDS2211P?

The TDS2211P uses a precision-triggered surge-rated FET as its main protection element. When an overvoltage event exceeds the trigger circuit's breakdown threshold, the drive circuit turns on the shunt FET, creating a low-impedance path to ground. This architecture - unlike passive TVS diodes - yields near-constant clamping voltage across current and temperature, and is explicitly documented in the TDS2211P datasheet functional diagram and application notes.

Can the TDS2211P be used to protect USB Type-C VBUS lines operating at 20V?

Yes, the TDS2211P is specifically validated for USB Type-C VBUS protection in Semtech's application documentation. Its 22V working voltage (V_RWM) and stable 27.5–28V clamping ensure safe operation within the USB PD specification's 20V maximum, even under worst-case 40A surge and +125°C ambient conditions - as confirmed in the TDS2211P datasheet Figure 4 and Application Information section.

How many pins must be connected for the TDS2211P to achieve its rated 40A peak pulse current?

All six pins of the TDS2211P must be connected: pins 1, 2, and 3 (GND) and pins 4, 5, and 6 (IN). The datasheet explicitly states that connecting all three GND pins with low-inductance vias and all three IN pins via a single straight trace is mandatory to achieve the full 40A (8/20μs) rating and optimal surge performance - per Pin Configuration section and PCB Layout Recommendation on page 6.

What is the junction capacitance of the TDS2211P, and where is it specified?

The TDS2211P has a junction capacitance of 175pF, measured at 22V reverse bias and 1MHz frequency. This value is listed in the Electrical Characteristics table on page 2 of the official TDS2211P datasheet (Rev 2.5, Nov 2021) under "Junction Capacitance (C_J)", and is confirmed in the Typical Characteristics plot on page 4 showing capacitance vs. reverse voltage.

Does the TDS2211P require a thermal pad or heatsink for 40A surge dissipation?

No, the TDS2211P does not require a thermal pad or external heatsink. As stated in the datasheet's PCB Layout Recommendation (page 6), energy is dissipated internally during transient events, and "no 'thermal pad' is needed." The device relies on low-inductance GND connections and proximity to the connector - not thermal mass - for effective surge handling, and its 1.6×1.6mm DFN package is qualified for 40A pulses without additional thermal management.