Taiwan Semiconductor Corporation MUR4L40H

Overview

MUR4L40H from Taiwan Semiconductor is an AEC-Q101-qualified ultra-fast recovery rectifier diode rated for 4 A average forward current and 400 V repetitive peak reverse voltage, with 50 ns reverse recovery time and 1.28 V max forward voltage at 4 A and 25°C, deployed in automotive-grade DC-DC converters and switching inverters.

For engineers reviewing the MUR4L40H datasheet, MUR4L40H pinout, MUR4L40H application, or MUR4L40H equivalent, key selection criteria include its DO-201AD package, 125 A surge rating, 175°C max junction temperature, glass-passivated junction, and halogen-free RoHS compliance-critical for high-reliability power conversion designs.

Technical Context

This single-die, unidirectional silicon rectifier features a glass-passivated PN junction enabling stable operation up to 175°C junction temperature and optimized for high-frequency switching in hard-switched topologies. Its 50 ns reverse recovery time minimizes switching losses during turn-off transitions in SMPS and freewheeling paths.

The device delivers 1.28 V forward voltage at full 4 A load and 25°C, with reverse leakage limited to 10 µA at 400 V and 25°C (250 µA at 125°C), and exhibits 65 pF junction capacitance at 1 MHz and 4 V reverse bias-key parameters governing EMI and dynamic loss behavior.

Key Specifications

Pinout & Package

Package: DO-201AD molded plastic case with pure tin-plated leads, UL 94V-0 rated compound, polarity indicated by cathode band, weight ≈ 1.20 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STTH4L06S and ON Semi MUR440, the MUR4L40H uniquely combines 400 V rating, AEC-Q101 qualification, and 1.28 V VF in DO-201AD-making it optimal for automotive 48 V systems requiring validated reliability without over-spec'ing voltage.

Availability

MUR4L40H 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 full traceability and long-term lifecycle support.

Supply support for MUR4L40H 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 discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, serving global automotive, industrial, and computing markets since 1979.

The MUR4L40H belongs to TSC's MUR4Lx ultra-fast rectifier product line, engineered specifically for high-efficiency, high-reliability power conversion in automotive and industrial environments where fast recovery, thermal stability, and qualification rigor are mandatory.

FAQ

What is the maximum junction temperature rating for the MUR4L40H?

The MUR4L40H has a maximum junction temperature (TJ) rating of +175°C, verified per AEC-Q101 stress testing. This allows reliable operation in under-hood automotive environments and enclosed industrial enclosures. Thermal design must maintain TJ ≤ 175°C using the specified RθJL = 15°C/W and actual lead temperature measurements. The MUR4L40H achieves this via glass-passivated die construction and DO-201AD package thermal characteristics.

Is the MUR4L40H pin-compatible with standard DO-201AD rectifiers like 1N5408?

No-the MUR4L40H uses the DO-201AD package but is not functionally or electrically interchangeable with general-purpose rectifiers like 1N5408. While both share the same outline and two-terminal configuration, the MUR4L40H offers 50 ns trr and 400 V VRRM versus 1N5408's ~2 µs trr and 1000 V VRRM. Substituting without circuit re-evaluation risks excessive switching loss or voltage overshoot. The MUR4L40H is designed for high-frequency switching, not line-frequency applications.

Does the "H" suffix in MUR4L40H indicate AEC-Q101 qualification?

Yes-the "H" suffix in MUR4L40H explicitly denotes AEC-Q101 qualification per Taiwan Semiconductor's ordering nomenclature. This means the MUR4L40H has undergone full stress testing including HTGB, HTRB, TC, AC/DC life test, and ESD per AEC-Q101 Rev D. Non-H variants (e.g., MUR4L40) lack this qualification and are intended for industrial or commercial use only. The MUR4L40H's qualification data is documented in TSC's official AEC-Q101 report for the MUR4Lx family.

What is the reverse leakage current specification for MUR4L40H at elevated temperature?

The MUR4L40H specifies a maximum reverse leakage current (IR) of 250 µA at 400 V and TJ = 125°C, per the Electrical Specifications table. At 25°C and 400 V, IR is limited to 10 µA. This elevated leakage at high temperature is typical for silicon rectifiers and must be accounted for in low-power standby circuits. The MUR4L40H's glass-passivated junction helps stabilize IR drift across temperature cycles compared to epoxy-passivated alternatives.

Can MUR4L40H be used in synchronous rectification topologies?

No-the MUR4L40H is a passive silicon rectifier diode and cannot replace active MOSFETs in synchronous rectification. It lacks gate control and cannot be turned off actively. However, the MUR4L40H serves as a robust freewheeling or output rectifier in non-synchronous topologies (e.g., flyback, forward, or boost converters) where its 50 ns trr and low Qrr reduce losses relative to standard recovery diodes. For true synchronous rectification, discrete MOSFETs or dedicated SR controllers must be used instead of the MUR4L40H.