Semtech Corporation TCLAMP2482S.TCT

Overview

TClamp2482S.TCT from Semtech is a low-capacitance transient voltage suppression (TVS) array designed for secondary surge and ESD protection of G.Fast and VDSL2 Class-H line drivers. It features 24V reverse stand-off voltage, 30A 8/20µs surge current rating, 2.5pF maximum junction capacitance, snap-back crow-bar clamping action, and operates across –40°C to +85°C. It is deployed in central office and customer premise DSL equipment.

For engineers reviewing the TClamp2482S.TCT datasheet, pinout, applications, or equivalent options, key selection criteria include its 24V working voltage, 9.5V clamping voltage at 30A, SOT-23-6L flow-through package layout, bias-enabled low-capacitance performance, and compliance with IEC 61000-4-2/4-4/4-5.

Technical Context

The TClamp2482S.TCT integrates steering diodes with a high-power silicon-avalanche TVS using snap-back ("crow-bar") technology to achieve low clamping voltage (9.5V) under 30A 8/20µs surge stress. Its biased bridge architecture prevents signal distortion by pre-charging TVS capacitance via external bias applied to Pin 5.

It supports dual-voltage configurations: Pin 2 connects to negative bias in VDSL applications, while Pin 5 accepts positive bias; Pin 1 and Pin 3 serve as differential line terminals (Line 1A/1B), and Pin 6 is NC. Capacitance remains stable (≤2.5pF, ≤0.4pF variation from 1V–24V) to preserve DSL signal integrity.

Key Specifications

Pinout & Package

Package: JEDEC-standard SOT-23-6L, Pb-free matte tin finish, UL 94V-0 molding compound, tape-and-reel packaging (3000 pcs/reel).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SP1015-02UTG and SRV05-4, the TClamp2482S.TCT uniquely delivers 24V working voltage, 30A surge capability, and bias-controlled low capacitance in a flow-through SOT-23-6L - making it the only validated solution for VDSL2 Class-H and G.Fast secondary protection per ITU-T K-series standards.

Availability

TClamp2482S.TCT is available at Aetrix Electronics and suitable for DSL access equipment, G.Fast customer premise modems, and VDSL2 central office line cards requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for TClamp2482S.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 ICs for power management, protection, sensing, and wireless applications.

The TClamp® family was engineered specifically for secondary surge and ESD protection in high-speed wired communications-targeting DSL, G.Fast, and broadband access infrastructure where low capacitance, precise clamping, and bias stability are mandatory.

FAQ

What is the maximum clamping voltage of TClamp2482S.TCT under IEC 61000-4-5 surge conditions?

The TClamp2482S.TCT clamps to a maximum of 9.5V when subjected to a 30A 8/20µs surge waveform per IEC 61000-4-5. This value is measured across Pins 1–3 using a 1.2/50µs voltage and 8/20µs current combination waveform with 2Ω source impedance, and reflects the peak voltage after snap-back activation. The TClamp2482S.TCT maintains this clamping performance across its full operating temperature range (–40°C to +85°C).

How does the bias configuration differ between G.Fast and VDSL2 applications for TClamp2482S.TCT?

In G.Fast single-ended applications, Pin 2 of the TClamp2482S.TCT is connected to ground while Pin 5 receives positive bias (e.g., +24V); in VDSL2 dual-voltage configurations, Pin 2 connects to negative bias (e.g., –12V) and Pin 5 to positive bias (e.g., +12V). This dual-bias arrangement stabilizes the internal bridge capacitance across the full differential swing, preventing signal distortion. The TClamp2482S.TCT datasheet specifies resistor values of 100kΩ to 1MΩ for R1/R2 to minimize leakage.

Is TClamp2482S.TCT compatible with automated SMT assembly processes?

Yes, the TClamp2482S.TCT uses a standard JEDEC SOT-23-6L package with matte tin lead finish, fully compliant with Pb-free reflow soldering profiles (J-STD-020). Its land pattern matches IPC-7351B density level 'N', and the device is supplied in EIA-481-compliant tape-and-reel format (3000 units per 7-inch reel). The TClamp2482S.TCT has been qualified for MSL Level 1 per J-STD-020, eliminating bake requirements prior to assembly.

What is the guaranteed junction capacitance range for TClamp2482S.TCT at 1MHz?

The TClamp2482S.TCT guarantees a junction capacitance of 1.2pF minimum to 2.5pF maximum at VR = 0V, f = 1MHz, measured between Pins 1 and 3 at 25°C. Capacitance variation across the 1V–24V reverse bias range is limited to 0.4pF maximum - a critical specification ensuring consistent impedance matching and minimal return loss in high-frequency DSL signal paths. These values are production-tested per datasheet specifications.

Can TClamp2482S.TCT be used without external bias resistors?

No - the TClamp2482S.TCT requires external bias resistors (R1, R2) connected to Pins 2 and 5 to pre-charge its internal TVS capacitance and prevent signal distortion during line activation. Operating the TClamp2482S.TCT without bias results in transient charging artifacts that degrade DSL/G.Fast signal integrity, especially during startup or line retraining. The recommended resistor range is 100kΩ to 1MΩ, selected to balance leakage current and voltage drop across temperature extremes.