STMicroelectronics SMP100LC-270

Overview

SMP100LC-270 from STMicroelectronics is a bidirectional thyristor surge suppressor (TSS) designed for fail-safe overvoltage protection on telecom and industrial data lines. It features a 270 V breakover voltage (V_BO), 100 A repetitive peak pulse current (10/1000 μs), 60 pF capacitance at 2 V, ≤2 μA leakage current, and 30 mA minimum holding current (I_H). It protects xDSL and Ethernet line cards against lightning surges per IEC 61000-4-5 and ITU-T K20/K21.

For engineers reviewing the SMP100LC-270 datasheet, SMP100LC-270 pinout, SMP100LC-270 application, or SMP100LC-270 equivalent, key selection criteria include bidirectional crowbar action, low signal-line capacitance, fail-safe short-circuit mode under fault, compliance with GR-1089 Core and UL497B, and SMB (DO-214AA) package compatibility with high-density PCB layouts.

Technical Context

The SMP100LC-270 operates as a voltage-triggered bidirectional thyristor that latches into low-impedance conduction upon exceeding its dynamic breakover voltage (345 V max) and remains conducting until current falls below 30 mA holding threshold. Its fail-safe behavior ensures robust short-circuit clamping during sustained overvoltage events.

Designed for telecom line protection, it delivers low 60 pF junction capacitance at 2 V bias and 1 MHz, enabling minimal signal distortion on high-speed digital interfaces. Thermal resistance is 100 °C/W (junction-to-ambient, with recommended footprint), supporting operation from –40 °C to +150 °C junction temperature.

Key Specifications

Pinout & Package

SMP100LC-270 uses the SMB (DO-214AA) package: two-terminal, symmetrical, bidirectional device with cathode/anode terminals marked by polarity band on one end. Leads are lead-free, halogen-free, and rated for 260 °C soldering (10 s).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMCJ27CA and TPSMD270A, SMP100LC-270 uniquely provides certified bidirectional crowbar action with UL497B recognition, 100 A surge endurance, and 60 pF capacitance-making it the sole choice for standards-compliant telecom line card primary protection.

Availability

SMP100LC-270 is available at Aetrix Electronics and suitable for xDSL line cards, industrial RS-485 networks, telecom remote terminal units, and Ethernet PHY interface protection requiring stable component supply and long-term lifecycle assurance.

Supply support for SMP100LC-270 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 GR-1089, ITU-T K20/K21, and UL497B requirements for fail-safe, low-capacitance surge suppression in high-speed data line applications.

FAQ

What is the fail-safe behavior of SMP100LC-270 during sustained overvoltage?

The SMP100LC-270 enters a latched low-impedance state (short-circuit mode) when triggered, remaining conductive until line current drops below its 30 mA minimum holding current. This ensures continuous protection even during prolonged AC faults, unlike TVS diodes that may thermally fail open-circuit.

Does SMP100LC-270 require a series current-limiting resistor in telecom applications?

No external series resistor is required for GR-1089 Core first-level compliance, as confirmed in Table 1 of DS1916. The device's intrinsic dynamic resistance and thermal design allow direct placement across protected lines when used with standard telecom transformer coupling and isolation.

How does SMP100LC-270 differ from standard TVS diodes in surge response?

Unlike TVS diodes that clamp with voltage-dependent resistance and degrade under repeated surges, SMP100LC-270 uses thyristor-based crowbar action with no wear-out mechanism. It exhibits zero aging, maintains consistent 345 V dynamic V_BO over lifetime, and provides guaranteed short-circuit failure mode per UL60950.

Can SMP100LC-270 be used on 24 V DC industrial control lines?

Yes - its 243 V maximum reverse standoff voltage (V_RM) and 345 V dynamic breakover ensure safe operation on 24 V DC buses. It activates only during surge events exceeding 345 V, avoiding interference with normal system operation or PLC I/O signaling.