STMicroelectronics TPA180

Overview

TPA180 from STMicroelectronics is a bidirectional Trisil™ thyristor surge protection device in DO-15 package, designed for telecom line-level transient suppression with 180 V standoff voltage, 235 V dynamic breakover voltage, 14 mA minimum holding current, 25 pF capacitance at 50 V, and 50 A repetitive peak pulse current (10/1000 µs). It protects analog/digital xDSL and T1/E1 line cards against lightning surges per GR-1089 Core and ITU-T K20/K21.

For engineers reviewing the TPA180 datasheet, TPA180 pinout, TPA180 application, or TPA180 equivalent, key selection criteria include bidirectional crowbar behavior, fail-safe short-circuit mode under overvoltage, UL497B and UL94 V0 certification, DO-15 mechanical compatibility, and compliance with FCC Part 68 lightning surge Type A/B requirements.

Technical Context

The TPA180 operates as a voltage-triggered bidirectional thyristor that latches into low-impedance conduction upon exceeding its dynamic breakover voltage (235 V), sustaining conduction until current falls below 14 mA holding threshold. Its fail-safe short-circuit mode ensures continued protection even after degradation.

Designed specifically for telecom primary-side surge protection, it meets GR-1089 Core first-level (2500 V, 10/1000 µs, 500 A) and ITU-T K20 (6000 V, 10/700 µs, 150 A) standards when used with appropriate series impedance-e.g., 37.5 Ω for K20 compliance. Thermal resistance junction-to-ambient is 100 °C/W with recommended DO-15 footprint.

Key Specifications

Pinout & Package

TPA180 is housed in a DO-15 axial-leaded package (JEDEC registered), with no polarity marking-functionally symmetric due to bidirectional operation. Leads are tin-plated copper, rated for 260 °C soldering (10 s), and meet RoHS/ECOPACK® requirements.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bidirectional telecom surge protection applications.

Compared with SMTPA180 and TPA200, TPA180 offers the best balance of proven DO-15 mechanical robustness, thermal performance (100 °C/W), and precise 180 V standoff for -48 V telecom line cards-making it the reference choice for xDSL and T1/E1 protection where reliability and manufacturability are prioritized over miniaturization or extended voltage range.

Availability

TPA180 is available at Aetrix Electronics and suitable for analog line cards (xDSL), digital line cards (T1/E1), and central office equipment requiring stable component supply, long-lifecycle support, and certified surge protection.

Supply support for TPA180 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, delivering innovative silicon solutions for automotive, industrial, and communications markets since 1987.

The Trisil™ product line was developed specifically for fail-safe, high-reliability surge protection in telecom infrastructure-targeting GR-1089, ITU-T K-series, and FCC Part 68 compliance with zero maintenance lifetime performance.

FAQ

What is the fail-safe behavior of TPA180 during end-of-life degradation?

TPA180 fails in a short-circuit mode, maintaining low-impedance conduction indefinitely once triggered. This ensures continued surge shunting even after repeated stress events, preventing open-circuit failure that would expose downstream components to unclamped transients-critical for telecom equipment safety certification.

How does TPA180 coordinate with a gas discharge tube (GDT) in a two-stage protection circuit?

In a typical telecom front-end, the GDT handles high-energy surges (>5 kA) with slower response, while TPA180 provides fast (<100 ns) clamping to limit let-through voltage to safe levels for downstream ICs. Their coordination relies on impedance matching: a 5–10 Ω series resistor isolates the stages, ensuring the GDT fires first and the TPA180 takes over during the voltage tail.

Can TPA180 be used in DC-powered applications like PoE injectors?

Yes-TPA180 is bidirectional and functions identically on DC lines. Its 180 V standoff and 235 V breakover make it suitable for protecting PoE data pairs against lightning-induced surges, provided the DC bias remains below 162 V (max VR) and series current limiting ensures holding current is not sustained unintentionally.

What is the maximum allowable series resistance when using TPA180 for FCC Part 68 lightning surge Type A compliance?

For FCC Part 68 Type A (1500 V, 10/160 µs), the maximum series resistance is 12.5 Ω to limit peak let-through voltage to 1500 V at 50 A. This value is derived from the standard's specified test condition and ensures the TPA180 triggers within specification while maintaining safe voltage across protected circuitry.