Infineon Technologies D251N18BXPSA1

Overview

D251N18BXPSA1 from eupec (now Infineon Technologies) is a high-power, press-pack silicon rectifier diode rated for 1800 V repetitive peak reverse voltage (VRRM), 250 A mean forward current (IFAVM) at 130 °C case temperature, and 6.3 kA non-repetitive surge current (IFSM). It features a 0.151 °C/W maximum junction-to-case thermal resistance and is designed for industrial DC link and traction converter applications requiring robust, two-sided cooled power handling.

For engineers reviewing the D251N18BXPSA1 datasheet, D251N18BXPSA1 pinout, D251N18BXPSA1 application, or D251N18BXPSA1 equivalent, key selection criteria include verified VRRM = 1800 V, IFAVM = 250 A @ tc = 130 °C, on-state voltage VT ≤ 1.57 V @ 800 A, clamping force of 3.5 kN, and pressure-contact Si-pellet construction with anode-to-case polarity.

Technical Context

This device is a stud-mounted, double-side cooled, press-pack power rectifier diode with anode-to-case polarity and no isolated mounting hardware. Its silicon pellet uses pressure contact (not soldered or bonded), enabling high-reliability operation under thermal cycling and mechanical stress in high-current inverters.

Thermal performance is defined by transient impedance ZthJC curves for DC and pulsed conditions, with distinct cooling configurations (anode-, cathode-, or two-sided). The 0.85 mΩ slope resistance (rT) and 0.8 V threshold voltage (VT(TO)) confirm its low-loss conduction behavior at rated junction temperature (tvj max = 180 °C).

Key Specifications

Pinout & Package

Package: Press-pack stud-mount (case design E/F), anode-to-case polarity, silicon pellet with pressure contact, Ø21 mm active area (Ø23 mm for 2000 V variants only), M20 thread, weight ≈ 175 g.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-power rectifier diode applications.

Compared with DD900S18K3C and SKKH 250/18E, D251N18BXPSA1 offers balanced trade-offs: identical voltage rating and base current capability as SKKH 250/18E but superior thermal resistance and pressure-contact reliability, while delivering lower cost than DD900S18K3C where 250 A suffices.

Availability

D251N18BXPSA1 is available at Aetrix Electronics and suitable for rail traction inverters, industrial medium-voltage drives, and high-power UPS systems requiring stable component supply and long-lifecycle support.

Supply support for D251N18BXPSA1 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

eupec GmbH (acquired by Infineon Technologies in 2000) specialized in high-power semiconductor devices for industrial and traction applications before full integration into Infineon's High Power Segment.

D251N18BXPSA1 belongs to eupec's D251N series of press-pack rectifiers, engineered for high-reliability, high-current DC link applications in harsh thermal and mechanical environments.

FAQ

What is the correct mounting torque for the cathode stud of D251N18BXPSA1?

The cathode stud requires an M20 thread tightening torque of 20 Nm. This ensures proper mechanical contact and thermal interface integrity. Under-torquing risks increased RthCK and localized heating; over-torquing may deform the stud or compromise pressure contact uniformity across the Si pellet surface.

Does D251N18BXPSA1 support two-sided cooling?

Yes - D251N18BXPSA1 is explicitly designed for double-sided cooling, with thermal data provided for anode-, cathode-, and two-sided configurations in its datasheet. Its case design E/F and pressure-contact construction enable effective heat extraction from both terminals, unlike solder-bonded alternatives limited to single-sided cooling.

Is the anode electrically connected to the case?

Yes - polarity is anode-to-case. The metal housing forms the anode terminal, meaning the case must be electrically isolated from ground or other potentials unless intentionally used as the anode node. This configuration is standard for press-pack rectifiers in series-stacked high-voltage assemblies.

What is the maximum allowable junction temperature during surge conditions?

The maximum junction temperature remains 180 °C even during non-repetitive surge events (e.g., IFSM = 6.3 kA, tp = 10 ms). Transient thermal impedance curves (ZthJC) confirm safe operation within this limit when initial junction temperature is ≤180 °C and heatsink thermal mass is sufficient to absorb pulse energy without exceeding tvj max.