Taiwan Semiconductor Corporation MUR840H

Overview

MUR840H from Taiwan Semiconductor is an AEC-Q101-qualified ultra-fast recovery rectifier diode in TO-220AC package, rated for 8 A average forward current, 400 V repetitive peak reverse voltage, and 50 ns reverse recovery time at IF = 0.5 A, IR = 1.0 A, Irr = 0.25 A. It delivers low forward voltage (1.300 V max at 8 A, 25°C) and high surge capability (100 A, 8.3 ms half-sine), targeting automotive-grade DC-DC converters and switching inverters.

For engineers reviewing the MUR840H datasheet, MUR840H pinout, MUR840H application, or MUR840H equivalent, key selection criteria include its AEC-Q101 qualification, 400 V VRRM rating, 50 ns trr performance, TO-220AC thermal resistance (2 °C/W), and glass-passivated junction reliability under high-temp, high-surge conditions.

Technical Context

The MUR840H employs a single-die, planar epitaxial construction with glass passivation to ensure stable junction behavior across -55°C to +175°C operating range. Its ultra-fast recovery (50 ns) enables efficient operation in high-frequency switching topologies above 100 kHz.

Thermal design is supported by a low junction-to-case resistance of 2 °C/W and matte tin-plated leads compliant with J-STD-002 solderability. Polarity is marked on the device body, and mounting torque must not exceed 0.56 N·m.

Key Specifications

Pinout & Package

Package: TO-220AC - 3-lead, single-ended vertical-mount power package with isolated tab (cathode-connected tab), UL 94V-0 molding compound, and matte tin-plated leads.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-fast rectifier applications.

Compared with STTH8R04DJF, MUR840H offers marginally higher VF but identical trr and qualification; versus MUR840E, it adds AEC-Q101 compliance without electrical trade-offs-making it the sole choice for automotive-grade designs requiring both performance and qualification assurance.

Availability

MUR840H is available at Aetrix Electronics and suitable for automotive DC-DC converters, industrial switching inverters, and renewable energy charge controllers requiring stable component supply with guaranteed AEC-Q101 compliance and long-term lifecycle support.

Supply support for MUR840H 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

Taiwan Semiconductor Corporation (TSC) is a vertically integrated analog and power discrete manufacturer headquartered in Hsinchu, Taiwan, serving global automotive, industrial, and computing markets since 1979.

The MUR840H belongs to TSC's MUR8xx ultra-fast rectifier family, engineered specifically for high-efficiency, high-reliability power conversion in automotive and industrial systems where fast recovery, thermal robustness, and qualification-grade reliability are mandatory.

FAQ

What is the maximum junction temperature rating for the MUR840H?

The MUR840H has a maximum junction temperature (TJ max) of +175°C, verified per AEC-Q101 stress testing. This rating allows operation in under-hood automotive environments and high-ambient industrial settings without thermal shutdown. Derating curves in the official datasheet define safe IF vs. TC limits, and the 2 °C/W RθJC enables precise thermal modeling. The MUR840H maintains stable VF and trr performance up to this limit when properly heatsinked.

Is the MUR840H pin-compatible with standard TO-220AC rectifiers like the 1N5408?

No - while the MUR840H uses the TO-220AC outline, it is not functionally or thermally interchangeable with general-purpose rectifiers like the 1N5408. The MUR840H features ultra-fast recovery (50 ns vs. >2000 ns), higher VRRM (400 V vs. 1000 V), and AEC-Q101 qualification. Its cathode-connected tab requires electrical isolation unless referenced to system ground. The MUR840H must be selected based on switching speed and qualification needs, not just package footprint.

Does the MUR840H have a built-in thermal protection feature?

No, the MUR840H is a passive discrete diode and does not include integrated thermal shutdown or sensing circuitry. Thermal management relies entirely on external design: proper heatsinking, PCB copper area, mounting torque ≤0.56 N·m, and adherence to the forward current derating curve. Its 175°C TJ max and 2 °C/W RθJC provide design headroom, but system-level thermal monitoring remains the responsibility of the power supply designer using the MUR840H.

What does the "H" suffix signify in MUR840H?

The "H" suffix in MUR840H explicitly denotes AEC-Q101 qualification per Taiwan Semiconductor's ordering nomenclature. It confirms that the device has passed all required stress tests-including high-temperature operating life (HTOL), temperature cycling (TC), and unbiased highly accelerated stress test (UHAST)-for automotive power semiconductor applications. Non-H variants (e.g., MUR840) lack this qualification and are intended for commercial/industrial use only.

Can the MUR840H be used in place of the MUR860 in a 400 V design?

Yes - the MUR840H is specifically rated for 400 V VRRM, making it the optimal fit for 400 V designs. Substituting the 600 V-rated MUR860 would incur unnecessary cost and slightly higher VF (1.700 V vs. 1.300 V), increasing conduction loss. The MUR840H's 50 ns trr and 2 °C/W RθJC match the MUR860's performance at its rated voltage, delivering better efficiency and thermal performance in 400 V applications than the over-spec'd MUR860.