STMicroelectronics SMP100LC-400

Overview

SMP100LC-400 from STMicroelectronics is a bidirectional thyristor surge suppressor (TSS) designed for fail-safe overvoltage protection on telecom and industrial data lines. It features 400 V breakover voltage (V_BO), 540 V dynamic peak voltage, 20 mA minimum holding current (I_H), 45 pF capacitance at 2 V, and 100 A repetitive peak pulse current (10/1000 μs). It protects xDSL/Ethernet interfaces against lightning surges per IEC 61000-4-5 and ITU-T K20/K21.

For engineers reviewing the SMP100LC-400 datasheet, SMP100LC-400 pinout, SMP100LC-400 application, or SMP100LC-400 equivalent, key selection criteria include bidirectional crowbar action, low 45 pF capacitance for high-speed line integrity, fail-safe short-circuit mode under fault, UL497B recognition, and SMB (DO-214AA) package compatibility with telecom PCB layouts.

Technical Context

The SMP100LC-400 operates as a voltage-triggered bidirectional thyristor that latches into low-impedance conduction upon exceeding its 400 V static breakover voltage, clamping transient energy until current falls below 20 mA holding threshold. Its fail-safe behavior ensures permanent short-circuit mode during end-of-life overstress, preventing open-circuit failure modes.

Designed for telecom line protection, it delivers 100 A surge handling (10/1000 μs), meets GR-1089 Core Level 1 (2500 V, 100 A), and supports 6000 V ITU-T K20 compliance with zero series resistance requirement. Low 45 pF capacitance at 2 V preserves signal integrity on >100 Mbps digital interfaces without distortion.

Key Specifications

Pinout & Package

SMP100LC-400 uses the SMB (DO-214AA) package: 5.6 mm × 3.95 mm × 2.45 mm body, gull-wing leads, UL94 V0 epoxy, lead-free plating, halogen-free molding compound. Thermal resistance 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 SMCJ40CA and TISP4240M3BJR-S, SMP100LC-400 uniquely combines 400 V breakover, fail-safe short-circuit behavior, and 45 pF capacitance - making it the only option qualified for primary-side protection in 400 V-rated telecom infrastructure meeting GR-1089 and ITU-T K20.

Availability

SMP100LC-400 is available at Aetrix Electronics and suitable for VDSL2 line cards, GPON ONUs, industrial RS-485 networks, and PoE-powered Ethernet devices requiring stable component supply across multi-year production cycles.

Supply support for SMP100LC-400 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, MCU, and sensor solutions for automotive, industrial, and communications markets.

The SMP100LC series belongs to ST's Telecom Circuit Protector product line, engineered specifically for fail-safe, low-capacitance surge suppression in high-speed wired communication infrastructure.

FAQ

What is the fail-safe behavior of SMP100LC-400 during end-of-life overstress?

Under catastrophic surge beyond its I_FS rating (5 kA, 8/20 μs), SMP100LC-400 enters permanent short-circuit mode instead of open-circuit failure. This ensures downstream circuitry remains protected and prevents fire hazard or uncontrolled voltage rise, satisfying UL60950 and IEC 62368-1 safety requirements.

Can SMP100LC-400 be used on 1000BASE-T Ethernet interfaces?

Yes - its 45 pF capacitance at 2 V and low leakage (2 μA at 360 V) preserve signal integrity up to 125 MHz, meeting IEEE 802.3ab requirements for Category 5e/6 cabling. It must be placed before magnetics and paired with common-mode chokes to handle differential-mode surges.

How does SMP100LC-400 differ from standard TVS diodes in surge response?

Unlike TVS diodes that clamp with voltage-dependent resistance, SMP100LC-400 acts as a voltage-triggered thyristor: it remains high-impedance until reaching 400 V, then snaps to <1 V on-state voltage with full current conduction. This provides sharper clamping, lower let-through energy, and inherent latching without gate control.

Is SMB (DO-214AA) footprint compatible with automated pick-and-place equipment?

Yes - the SMB package has standardized gull-wing leads (E = 5.1–5.6 mm, E1 = 4.05–4.60 mm, D = 3.30–3.95 mm) and is supported by all major SMT placement platforms. ST provides recommended solder paste stencil design and reflow profile in DS1916 Rev 15, Section 3.1.