STMicroelectronics SMP100LC-90

Overview

SMP100LC-90 from STMicroelectronics is a bidirectional thyristor surge suppressor (TSS) designed for fail-safe overvoltage protection on high-speed data lines. It features a 90 V breakover voltage (V_BO), 40 pF capacitance at 2 V, 2 μA max leakage current, 150 mA minimum holding current, and 100 A repetitive peak pulse current (10/1000 μs), enabling robust lightning and AC fault protection in xDSL and Ethernet line cards.

For engineers reviewing the SMP100LC-90 datasheet, SMP100LC-90 pinout, SMP100LC-90 application, or SMP100LC-90 equivalent, this device is selected for telecom-grade transient suppression where low capacitance, fail-safe short-circuit behavior, and compliance with GR-1089 Core, ITU-T K20/K21, and IEC 61000-4-5 are mandatory.

Technical Context

The SMP100LC-90 operates as a voltage-triggered bidirectional crowbar device that latches into low-impedance conduction upon exceeding its dynamic breakover voltage (120 V typ.) and remains conducting until current falls below 150 mA holding threshold. Its fail-safe mode ensures permanent short-circuit behavior under end-of-life surge stress, eliminating open-circuit failure risk.

Designed for placement directly across signal pairs, it delivers <40 pF capacitance at 2 V bias to preserve signal integrity up to 100 Mbps, while meeting stringent telecom surge standards including 5 kA fail-safe current rating (8/20 μs) and 100 A repetitive pulse handling without degradation.

Key Specifications

Pinout & Package

Package: DO-214AA (SMB), JEDEC-registered, UL94 V0 epoxy, lead-free and halogen-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SM100LC-90 and P6SMB90A, SMP100LC-90 uniquely combines UL497B recognition, bidirectional symmetry, sub-45 pF capacitance, and guaranteed fail-safe shorting-making it the only option qualified for primary-side telecom data line protection without design compromises.

Availability

SMP100LC-90 is available at Aetrix Electronics and suitable for DSLAM line cards, industrial Ethernet switches, central office protection modules, and telecom gateway designs requiring stable component supply and long-lifecycle support.

Supply support for SMP100LC-90 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 discrete components for industrial, automotive, and communications markets.

The SMP100LC series belongs to ST's Telecom Surge Protection product line, engineered specifically to meet GR-1089, ITU-T K-series, and IEC 61000-4-x standards for fail-safe, low-capacitance transient suppression on high-speed copper interfaces.

FAQ

What is the fail-safe behavior of SMP100LC-90 under end-of-life surge stress?

Under catastrophic overstress beyond its 5 kA (8/20 μs) fail-safe rating, SMP100LC-90 permanently shorts between terminals-guaranteeing continued circuit protection and preventing open-circuit failure that could leave downstream ICs unprotected. This behavior is inherent to its thyristor structure and verified per UL497B test protocols.

Can SMP100LC-90 be used on 1000BASE-T (Gigabit Ethernet) lines?

No-its 40 pF capacitance exceeds the typical ≤3 pF requirement for 1000BASE-T PHY interfaces. It is validated for 100BASE-TX and VDSL2 (up to 30 MHz), where capacitance-induced insertion loss and return loss remain within IEEE 802.3 specification limits.

Does SMP100LC-90 require a series current-limiting resistor?

No-its 150 mA minimum holding current and bidirectional crowbar action allow direct placement across protected lines without external resistors. Standards-compliant performance (e.g., GR-1089 Core Level 1) is achieved with zero series impedance, simplifying BOM and layout.

How does SMP100LC-90 differ from standard TVS diodes in telecom protection?

Unlike TVS diodes-which degrade with repeated surges and may fail open-SMP100LC-90 is a thyristor-based TSS with no wear-out mechanism and guaranteed fail-safe shorting. Its lower capacitance (vs. bidirectional TVS) and precise V_BO threshold enable tighter coordination with secondary protectors like GDTs in multi-stage telecom designs.