MUR840 Equivalent & Substitute Parts

Part Overview

The MUR840 is a general-purpose fast recovery rectifier diode manufactured by Taiwan Semiconductor Corporation. This through-hole component operates at 400 V DC reverse voltage with an 8 A average rectified current rating and features a 50 ns reverse recovery time. The device is housed in a TO-220AC package and is classified as Active product status with ROHS3 compliance. Substitute parts are identified to address inventory availability, regional sourcing requirements, or specific application performance parameters while maintaining electrical and mechanical compatibility within the TO-220-2 package family.

Substiute Parts

MUR840

Taiwan Semiconductor CorporationIn Stock: 2710MUR840 Datasheet

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SDUR840

SMC Diode SolutionsIn Stock: 1980SDUR840 Datasheet

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STTH30R04D

STMicroelectronicsIn Stock: 1745STTH30R04D Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the MUR840 are qualified based on the following critical parameters:

Mandatory Compatibility Criteria:

• Voltage - DC Reverse (Vr) (Max): 400 V minimum
• Package / Case: TO-220-2
• Mounting Type: Through Hole
• Speed Classification: Fast Recovery ≤ 500ns, > 200mA (Io)
• RoHS Status: ROHS3 Compliant

Current Rating Consideration: Substitute parts must support the application's current requirements. The MUR840 is rated for 8 A average rectified current. Substitutes with equal or higher current ratings are electrically compatible for this parameter.

Secondary Performance Parameters: Forward voltage drop (Vf), reverse recovery time (trr), and reverse leakage current are secondary differentiators that affect efficiency and switching characteristics but do not prevent substitution when primary criteria are met.

Parameter Comparison

Engineering Selection Recommendations

SDUR840 (SMC Diode Solutions): The SDUR840 maintains identical voltage rating (400 V) and forward voltage characteristics (1.3 V @ 8 A) as the MUR840. This substitute exhibits a faster reverse recovery time (45 ns versus 50 ns), which provides improved switching performance. The device is ROHS3 compliant and Active status. The operating temperature range is -55 to 150 °C, which is 25 °C lower at the maximum junction temperature compared to the MUR840. Selection of this substitute is appropriate for applications where the reduced upper temperature limit does not conflict with thermal design requirements. Current rating is not specified in available documentation.

STTH30R04D (STMicroelectronics): The STTH30R04D is rated for 30 A average rectified current, providing a 3.75× current capacity increase over the MUR840. The voltage rating remains 400 V, maintaining reverse voltage compatibility. Forward voltage is 1.45 V @ 30 A, representing a 0.15 V increase at the higher current level. Reverse recovery time is 100 ns, which is 50 ns longer than the MUR840. This substitute is suitable for applications requiring higher current handling capacity within the same voltage class and package form factor. The device maintains ROHS3 compliance and Active status with an operating temperature range of -40 to 175 °C.

Frequently Asked Questions (FAQ)

Q: Can the SDUR840 be used as a direct replacement for the MUR840?

A: The SDUR840 is electrically compatible for applications operating within the -55 to 150 °C junction temperature range. Both devices share identical 400 V reverse voltage rating, TO-220-2 package, and 1.3 V forward voltage at 8 A. The SDUR840 exhibits faster reverse recovery (45 ns), which is a performance advantage. Verify that your application's maximum junction temperature does not exceed 150 °C.

Q: When should the STTH30R04D be selected over the MUR840?

A: The STTH30R04D is selected when the application requires current handling above 8 A. With a 30 A rating, this device accommodates higher power rectification within the same 400 V voltage class and TO-220-2 package. The trade-off is increased forward voltage drop (1.45 V @ 30 A) and longer reverse recovery time (100 ns). Applications with lower switching frequency requirements benefit from this substitute.

Q: Are all three devices pin-compatible?

A: Yes. The MUR840, SDUR840, and STTH30R04D all use the TO-220-2 package with identical through-hole mounting configuration. PCB layout and thermal management considerations remain consistent across all three devices.

Q: What is the significance of reverse recovery time differences?

A: Reverse recovery time (trr) affects switching speed and electromagnetic interference characteristics. The MUR840 (50 ns) and SDUR840 (45 ns) are faster than the STTH30R04D (100 ns). Applications with high switching frequencies benefit from shorter reverse recovery times. Lower frequency applications are less sensitive to this parameter.

Q: Do all substitutes maintain RoHS3 compliance?

A: Yes. The MUR840, SDUR840, and STTH30R04D are all ROHS3 compliant. All three devices are classified as Active product status with unlimited moisture sensitivity level (MSL 1).

Q: What is the impact of reverse leakage current differences?

A: Reverse leakage current increases across the three devices: MUR840 (5 µA), SDUR840 (10 µA), and STTH30R04D (15 µA) at 400 V. Higher leakage current results in increased power dissipation during reverse bias conditions. Applications with stringent power efficiency requirements should account for this parameter when selecting substitutes.

Q: Can the STTH30R04D be used in applications designed for 8 A operation?

A: Yes. The STTH30R04D is rated for 30 A, which exceeds the 8 A requirement. The device operates safely at lower current levels. However, the increased forward voltage (1.45 V @ 30 A versus 1.3 V @ 8 A) and longer reverse recovery time (100 ns versus 50 ns) represent performance changes that may affect circuit efficiency and switching characteristics.