Infineon Technologies BAW78DH6327XTSA1

Overview

BAW78DH6327XTSA1 from Infineon Technologies is a silicon switching diode in SOT-89 package, configured as a single common-cathode dual diode with 400 V reverse voltage rating, 1 A continuous forward current, and 1 µs typical reverse recovery time-used in automotive power supply clamping and DC-DC converter freewheeling paths.

For engineers reviewing the BAW78DH6327XTSA1 datasheet, BAW78DH6327XTSA1 pinout, BAW78DH6327XTSA1 application, or BAW78DH6327XTSA1 equivalent, key selection criteria include VR = 400 V, IF = 1 A, trr = 1 µs, thermal resistance RthJS ≤ 25 K/W, and AEC-Q101 qualification for under-hood automotive use.

Technical Context

This diode operates as a high-voltage, fast-recovery switching device optimized for repetitive surge handling (IFSM = 10 A) and stable junction temperature up to 150 °C. Its SOT-89 package enables surface-mount integration in space-constrained power stages while maintaining low thermal resistance to soldering point (≤25 K/W).

The device exhibits low reverse leakage (IR ≤ 1 µA at 400 V, 25 °C; ≤50 µA at 150 °C) and controlled forward voltage drop (VF ≤ 1.6 V at IF = 1 A), supporting efficient energy transfer in flyback and boost topologies where voltage transients exceed 300 V.

Key Specifications

Pinout & Package

SOT-89 package: 3-pin thermally enhanced plastic surface-mount outline with exposed tab (pin 3) for heatsinking; pin 1 = anode 1, pin 2 = anode 2, pin 3 = common cathode.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage switching diode applications.

Compared with STTH1R04DJF and MUR120E, BAW78DH6327XTSA1 offers optimal balance of 400 V rating, 1 µs trr, and ≤25 K/W thermal resistance in SOT-89-making it preferred for automotive-grade 350–400 V clamping where thermal density and reliability outweigh raw speed.

Availability

BAW78DH6327XTSA1 is available at Aetrix Electronics and suitable for automotive engine control units, industrial DC-DC converters, and on-board charger auxiliary supplies requiring stable component supply and AEC-Q101 compliance.

Supply support for BAW78DH6327XTSA1 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 AG is a German semiconductor manufacturer specializing in power management, automotive electronics, and industrial control ICs and discrete devices.

BAW78DH6327XTSA1 belongs to Infineon's AEC-Q101-qualified silicon switching diode product line, designed specifically for high-reliability automotive power conversion and transient suppression in harsh thermal environments.

FAQ

What is the maximum allowable junction temperature for continuous operation?

The BAW78DH6327XTSA1 has a maximum junction temperature (Tj) rating of 150 °C. This limit applies under continuous DC forward conduction at rated IF = 1 A, provided the thermal design maintains RthJS ≤ 25 K/W and solder-point temperature does not exceed 125 °C per datasheet derating curves.

Is this diode suitable for use in a 400 V DC bus clamping circuit?

Yes-the device is rated for VR = 400 V and VRM = 400 V, with verified breakdown voltage V(BR) ≥ 400 V at I(BR) = 100 µA. It is routinely deployed in 350–400 V automotive DC bus clamping applications where transient suppression must remain effective up to rated voltage without avalanche degradation.

Does the SOT-89 package require special PCB layout considerations for thermal performance?

Yes-pin 3 (common cathode) is the thermal tab. To achieve RthJS ≤ 25 K/W, a minimum 25 mm² copper pour (2 oz thickness) connected directly to pin 3 is required. Thermal vias (≥4×0.3 mm) beneath the tab and connection to internal ground planes further reduce junction-to-ambient resistance by up to 30%.

How does the dual-anode configuration benefit circuit design?

The dual-anode, common-cathode topology allows independent connection of two high-side switching nodes (e.g., dual injectors or dual half-bridges) to a shared low-side return. This reduces component count versus two discrete diodes, improves layout symmetry, and minimizes parasitic inductance in critical power paths-especially valuable in tight-space automotive ECU designs.