Infineon Technologies STT1900N18P55XPSA1

Overview

STT1900N18P55XPSA1 from Infineon Technologies is a pressure-contact soft starter module integrating two anti-parallel thyristor arms in a single package, rated for 1800 V repetitive peak off-state voltage (VDRM/VRRM), 1900 A 21-second overload current, and 17,000 A non-repetitive surge current (ITSM). It features an integrated optimized heatsink, 0.28 mΩ slope resistance (rT), and 0.9 V threshold voltage (VT0), designed for industrial motor soft-starting and static switching applications.

For engineers reviewing the STT1900N18P55XPSA1 datasheet, STT1900N18P55XPSA1 pinout, STT1900N18P55XPSA1 application, or STT1900N18P55XPSA1 equivalent, key selection criteria include its 155 °C maximum junction temperature after start, 0.084 K/W junction-to-ambient thermal resistance (RthJA) under 21 s duty, and gate trigger parameters (IGT ≤ 200 mA, VGT ≤ 2 V) for reliable phase-controlled turn-on in high-power AC line applications.

Technical Context

This module implements a dual-arm, anti-parallel thyristor configuration with pressure-contact die attachment, enabling high-current commutation without wire bonds. Its AMPT (Advanced Medium Power Technology) architecture supports sinusoidal conduction angles from 30° to 180°, with validated transient thermal impedance ZthJA and ZthJR models for accurate thermal design under pulsed and continuous loads.

The device operates as a line-commutated, gate-controlled power switch: turn-on is initiated by a 1–2 V, ≤200 mA gate pulse with <3 µs delay (tgd), while turn-off relies on natural current zero-crossing and controlled dv/dt (critical rate 1000 V/µs) and di/dt (250 A/µs) immunity. It is not self-commutated and requires external gate drive timing synchronized to AC phase.

Key Specifications

Pinout & Package

STT1900N18P55XPSA1 uses a pressure-contact, baseplate-mounted module package with isolated copper terminals. The mechanical housing includes front-side reference point for thermal resistance measurement (RthJR), M6 terminal screws (10 Nm ±10%), and DIN 46244 A control terminals (2.8 × 0.8 mm).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-current soft starter applications.

Compared with STT1600N18P55XPSA1 and STT2200N18P55XPSA1, the STT1900N18P55XPSA1 provides optimal balance of overload headroom, thermal performance, and system integration-delivering 1900 A capability without requiring larger mechanical interfaces or sacrificing gate drive simplicity.

Availability

STT1900N18P55XPSA1 is available at Aetrix Electronics and suitable for motor soft starters, static bypass switches, industrial power controllers, and static transfer switches requiring stable component supply, long-term lifecycle support, and traceable thermal performance validation.

Supply support for STT1900N18P55XPSA1 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

Infineon Technologies is a German semiconductor manufacturer specializing in power semiconductors, microcontrollers, and sensor solutions, with leadership in industrial, automotive, and energy-efficient systems.

This part belongs to Infineon's Soft Starter Module product line, engineered specifically for high-reliability, medium-power AC motor control and static switching-emphasizing pressure-contact robustness, integrated thermal management, and gate-drive simplicity in harsh industrial environments.

FAQ

What is the maximum allowable gate trigger pulse width for reliable operation?

The STT1900N18P55XPSA1 supports gate pulses up to 10 ms at 40 W peak power (PGM), with shorter durations permitting higher peak power: 1 ms at 80 W, 0.5 ms at 100 W, and 0.1 ms at 150 W. Exceeding these limits risks gate junction overheating and permanent degradation. Pulse width must also satisfy minimum latching current (IL ≤ 1200 mA) and holding current (IH ≤ 300 mA) requirements to ensure turn-on stability.

Can this module be used in three-phase configurations without external isolation?

Yes-STT1900N18P55XPSA1 is rated for use in three-phase soft starter topologies with appropriate phase isolation. Its baseplate is electrically isolated (6.3 mm creepage), and each arm operates independently. However, three-phase systems require three modules (one per phase) with synchronized gate drives and shared heatsink mounting; no internal phase-to-phase isolation exists within a single module.

How does the 155 °C Tvj max st rating affect thermal design?

The 155 °C maximum junction temperature after start allows temporary operation above the standard 125 °C limit during motor ramp-up, provided vR/vD remains below 80% of VRRM/VDRM. This enables longer acceleration profiles without thermal shutdown but requires transient thermal modeling using ZthJA analytical data (page 5) rather than steady-state RthJA alone.

Is forced-air cooling mandatory, or can conduction cooling suffice?

Conduction cooling alone is insufficient for full-rated operation. The specified RthJA = 0.084 K/W assumes vAir = 3.6 m/s forced airflow. With passive cooling, RthJA degrades significantly (e.g., 0.087 K/W at vAir = 2 m/s); sustained 1900 A loads would exceed junction limits. A heatsink with active airflow and thermal interface material is mandatory for compliance with 21 s overload and continuous ratings.