Onsemi MUR460G Ultrafast Rectifier: Datasheet, Application Circuit, and Replacement Guide
The Onsemi MUR460G is a high-efficiency ultrafast rectifier diode designed for use in high-frequency power conversion circuits. As a critical component in switch-mode power supplies (SMPS), inverters, and freewheeling/clamp diode applications, its performance is vital for system efficiency and reliability. This article provides a detailed overview of its datasheet specifications, a typical application circuit, and guidance for selecting a suitable replacement.
Datasheet Overview and Key Specifications
The MUR460G is part of Onsemi's family of ultrafast rectifiers, renowned for their very fast recovery time and low forward voltage drop. Key electrical characteristics from its datasheet include:
Repetitive Peak Reverse Voltage (VRRM): 600 V
Average Forward Rectified Current (IO): 4.0 A
Peak Forward Surge Current (IFSM): 150 A (non-repetitive)
Forward Voltage Drop (VF): Typically 1.25 V at 4.0 A
Reverse Recovery Time (trr): A maximum of 60 ns, which is crucial for minimizing switching losses and electromagnetic interference (EMI) in high-speed switching environments.
The device is housed in a DO-201AD package, offering a robust physical form factor for through-hole mounting (THT) and good thermal characteristics.
Typical Application Circuit
A primary application for the MUR460G is as a freewheeling diode in switch-mode power supplies, such as flyback converters. In this role, it provides a path for inductive current to flow when the main power switch (e.g., a MOSFET) turns off, protecting the switch from voltage spikes and improving overall efficiency.
In the circuit above, the MUR460G is placed across the transformer's primary winding or an inductive load. When the MOSFET switches off, the collapsing magnetic field induces a current that circulates through the MUR460G, safely dissipating the stored energy. Its ultrafast recovery time ensures this action happens quickly, preventing significant reverse recovery current from causing excessive heat and potential device failure.
Replacement Guide
When the MUR460G is unavailable, selecting an appropriate replacement requires careful consideration of several parameters to ensure compatibility and performance:
1. Voltage and Current Ratings: The replacement must have a VRRM of at least 600V and an average forward current (IO) of 4A or higher.
2. Recovery Time (trr): Choose a diode with an equivalent or faster trr (e.g., ≤ 60 ns). A slower diode will increase switching losses and cause overheating.
3. Forward Voltage (VF): A similar or lower VF is desirable to maintain efficiency.
4. Package Type: The DO-201AD package is common. Ensure the physical package and pin configuration are compatible for easy mounting.
Suitable potential replacements could include:
STMicroelectronics STTH4R06: (600V, 4A, trr 40 ns)
Diodes Incorporated UF4006: (600V, 1A, trr 50 ns) – Note: Current rating is lower; only suitable if derated for the application.
Vishay ES1J: (600V, 1A, trr 35 ns) – Note: Current rating is lower.
Always cross-reference the complete datasheets of any potential substitute to confirm all operational parameters are met for your specific design.
ICGOODFIND Conclusion
The Onsemi MUR460G stands as a reliable and efficient solution for high-frequency rectification. Its optimized balance of high voltage capability, low forward loss, and ultrafast switching makes it a cornerstone component in modern power electronics. Understanding its key specifications and circuit function is essential for both design and effective troubleshooting or component substitution.
Keywords: Ultrafast Rectifier, Switching Power Supply, Freewheeling Diode, Reverse Recovery Time, Forward Voltage Drop.
