STMicroelectronics SMP100LC-140

Overview

SMP100LC-140 from STMicroelectronics is a bidirectional thyristor surge suppressor (TSS) designed for fail-safe overvoltage protection on high-speed data lines. It features a 140 V breakover voltage (V_BO), 100 A repetitive peak pulse current (10/1000 µs), 65 pF capacitance at 2 V, ≤2 µA leakage current, and 30 mA minimum holding current (I_H). It is used in xDSL and Ethernet line cards to prevent signal distortion while meeting GR-1089 Core and ITU-T K20/K21 standards.

For engineers reviewing the SMP100LC-140 datasheet, SMP100LC-140 pinout, SMP100LC-140 application, or SMP100LC-140 equivalent, key selection criteria include bidirectional crowbar behavior, low capacitance for signal integrity, fail-safe short-circuit mode under fault, and compliance with telecom surge immunity standards including IEC 61000-4-5 and UL497B.

Technical Context

The SMP100LC-140 operates as a voltage-triggered bidirectional thyristor that latches into low-impedance conduction upon exceeding its static breakover voltage of 175 V (max) and dynamic breakover voltage of 180 V (max). Its fail-safe short-circuit mode ensures equipment protection even after repeated surges without degradation.

It delivers 100 A surge handling per 10/1000 µs waveform with thermal resistance R_th(j-a) = 100 °C/W and junction temperature range from –40 °C to +150 °C. The device requires no external trigger circuitry and maintains stable V_BO across temperature due to integrated thermal compensation.

Key Specifications

Pinout & Package

Package: DO-214AA (SMB), surface-mount, two-terminal device with cathode and anode terminals. Dimensions: 3.30–3.95 mm length × 5.10–5.60 mm width × 1.90–2.45 mm height. Thermal resistance: R_th(j-l) = 20 °C/W, R_th(j-a) = 100 °C/W (with recommended footprint).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar thyristor surge suppressor applications.

Compared with SMCJ130CA and P6SMB150A, the SMP100LC-140 provides bidirectional crowbar action, fail-safe short-circuit behavior, and 65 pF capacitance-making it uniquely suitable for high-speed telecom data line protection where reliability and signal fidelity are jointly critical.

Availability

SMP100LC-140 is available at Aetrix Electronics and suitable for DSL line cards, Ethernet PHY interfaces, telecom central office equipment, and building entrance protection units requiring stable component supply and long-term lifecycle support.

Supply support for SMP100LC-140 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, power, microcontroller, and sensor solutions for industrial, automotive, and communications markets.

The SMP100LC series belongs to ST's Telecom Circuit Protector product line, engineered specifically to meet stringent GR-1089, ITU-T K20/K21, and IEC 61000-4-5 surge immunity requirements for high-data-rate copper interface protection.

FAQ

What is the fail-safe behavior of SMP100LC-140 during end-of-life surge events?

The SMP100LC-140 enters a permanent low-impedance short-circuit state when subjected to surge energy beyond its I²t rating (20 A²s at 16.6 ms). This fail-safe mode prevents open-circuit failure and maintains downstream equipment isolation, unlike TVS diodes that degrade to high-impedance.

Can SMP100LC-140 be used in AC power line protection?

No. The SMP100LC-140 is rated for signal-line protection only, with maximum continuous reverse voltage of 126 V and operating junction temperature up to +150 °C. It lacks the voltage margin, thermal mass, and creepage/clearance design required for mains AC applications.

How does SMP100LC-140 coordinate with a gas discharge tube (GDT) in two-stage protection?

When placed downstream of a GDT, the SMP100LC-140 provides fast secondary clamping after GDT ionization. Its 175 V static V_BO ensures triggering only after the GDT fires (~350–500 V), limiting let-through voltage to <200 V and protecting sensitive PHY ICs.

Is SMP100LC-140 compatible with lead-free reflow soldering processes?

Yes. The device uses lead-free plating and halogen-free molding resin, with maximum lead temperature tolerance of 260 °C for 10 seconds. It complies with JEDEC J-STD-020 moisture sensitivity level (MSL) 1 and supports standard Pb-free reflow profiles.