STMicroelectronics TN2540-12G

Overview

TN2540-12G from STMicroelectronics is a standard silicon-controlled rectifier (SCR) in D²PAK surface-mount package, rated for 25 A RMS on-state current and 1200 V repetitive peak off-state voltage, with maximum gate trigger current of 40 mA. It delivers high static/dynamic commutation immunity at 125 °C junction temperature (dl/dt = 50 A/µs, dV/dt = 1500 V/µs), and is ECOPACK®2-compliant. It is deployed in solar and wind inverters for AC line switching under high dv/dt stress.

For engineers reviewing the TN2540-12G datasheet, TN2540-12G pinout, TN2540-12G application, or TN2540-12G equivalent, key selection criteria include verified 1200 V blocking capability, 25 A thermal derating at 102 °C case temperature, gate sensitivity down to 4 mA minimum IGT, and D²PAK anode-on-backside layout for heatsink-integrated mounting in industrial power converters.

Technical Context

This SCR operates as a unidirectional, gate-triggered power switch in phase-controlled rectification and AC line control topologies. Its design supports zero-crossing or random-phase triggering with robust noise immunity-enabled by 1500 V/µs dV/dt rating at Tj = 125 °C and low 40 mA max IGT.

Thermal performance is defined by Rth(j-c) ≤ 1.0 °C/W, enabling direct heatsink mounting via the anode tab. The device sustains non-repetitive surge currents up to 314 A (8.3 ms) and exhibits low on-state voltage drop (VTM ≤ 1.60 V at 50 A, 25 °C) and dynamic resistance (RD ≤ 14 mΩ at 125 °C).

Key Specifications

Pinout & Package

The TN2540-12G uses a D²PAK (TO-263) surface-mount package with anode connected to the exposed metal backside tab for direct heatsink mounting. Cathode and gate are accessible on the front-side leads.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SCR-based AC power control applications.

Compared with MCR25N1200 and SC25E12, the TN2540-12G uniquely combines D²PAK SMD form factor, 1500 V/µs dV/dt, and 1.0 °C/W thermal resistance-making it optimal for space-constrained, high-reliability renewable energy and UPS systems requiring minimal snubbing and efficient thermal management.

Availability

TN2540-12G is available at Aetrix Electronics and suitable for solar inverters, industrial soft starters, and uninterruptible power supplies requiring stable component supply, long-term lifecycle support, and RoHS-compliant manufacturing.

Supply support for TN2540-12G 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 industrial, automotive, and consumer markets.

The TN2540-12G belongs to ST's high-voltage SCR product line, engineered specifically for ruggedized AC power control in renewable energy, UPS, and industrial motor systems where reliability under high dv/dt and thermal stress is critical.

FAQ

What is the maximum junction temperature and how does it affect derating?

The TN2540-12G has a maximum operating junction temperature of +125 °C. At this temperature, its IT(RMS) rating drops to 25 A only when case temperature is maintained at 102 °C-requiring active or large passive heatsinking. Derating curves in Figure 2 show IT(AV) falls to ~12 A at TCASE = 75 °C, making thermal interface design essential for sustained full-load operation.

Can TN2540-12G be used in bidirectional AC switching applications?

No-TN2540-12G is a unidirectional SCR and cannot block reverse voltage or conduct in reverse polarity. For bidirectional AC switching, two SCRs must be connected in inverse-parallel, or a TRIAC such as ST's BTB16-800BW should be used instead. Its VRRM rating applies only to forward-blocking mode.

Is the D²PAK anode tab electrically isolated from the PCB copper?

No-the anode is directly connected to the exposed metal backside tab and is not electrically isolated. A thermally conductive but electrically insulating pad (e.g., ceramic or polyimide) must be used between the tab and heatsink if the heatsink is grounded or at a different potential than the anode circuit.

What gate drive circuitry is recommended for reliable triggering?

A pulse-type gate driver delivering ≥4 mA (min), ≤40 mA (max), with ≤1.3 V gate-to-cathode voltage and <100 ns rise time is recommended. Optocouplers like MOC3021 (with zero-crossing detection) or discrete transistor drivers with RC snubbing on the gate line improve noise immunity-especially critical given the device's sensitivity to dv/dt-induced false triggering.