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onsemi MUR840G
- Part No.:
- MUR840G
- Manufacturer:
- onsemi
- Category:
- Single Diodes
- Package:
- TO-220-2
- Datasheet:
-
MUR840G.pdf
- Description:
- DIODE GEN PURP 400V 8A TO220-2
- Quantity:
- Payment:
- Shipping:
Inventory:917
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Product details
Overview
MUR840G from onsemi is an ultrafast recovery rectifier diode designed for high-frequency switching power supplies, inverters, and freewheeling applications. It delivers 8.0 A average forward current at TC = 150°C, supports 400 V peak repetitive reverse voltage (VRRM), exhibits 50 ns maximum reverse recovery time (trr), and operates up to 175°C junction temperature - enabling compact, thermally robust DC/DC and AC/DC converter designs in industrial SMPS.
For engineers reviewing the MUR840G datasheet, pinout, applications, or equivalent options, key selection criteria include its TO-220AC package thermal resistance (RJC = 2.0°C/W), low 1.20 V forward voltage at 8.0 A/150°C, 100 A nonrepetitive surge rating, and AEC-Q101 qualification for automotive-grade reliability validation.
Technical Context
The MUR840G employs a planar epitaxial silicon PN junction optimized for ultrafast soft recovery, minimizing switching losses and EMI in hard-switched topologies. Its 50 ns trr is measured under standardized conditions (IF = 1.0 A, di/dt = 50 A/μs), with guaranteed performance across −65°C to +175°C operating range.
Thermal design is enabled by a low RJC of 2.0°C/W and case-mounted construction, allowing direct heatsink attachment. The device features low leakage (5.0 μA max at VR = 400 V, TJ = 25°C) and low forward voltage (1.20 V max at IF = 8.0 A, TC = 150°C), supporting high-efficiency operation in continuous conduction mode (CCM) PFC and LLC resonant converters.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRRM | 400 V - Withstands peak reverse voltage in 400 V-class SMPS output rectification without breakdown. |
| IF(AV) | 8.0 A at TC = 150°C - Sustains full-rated DC output current when case temperature is held at 150°C via heatsinking. |
| trr | 50 ns - Enables operation up to ~200 kHz switching frequency with minimal reverse recovery loss and voltage overshoot. |
| vF (max) | 1.20 V at IF = 8.0 A, TC = 150°C - Reduces conduction loss and thermal load in high-current secondary-side rectification. |
| RJC | 2.0°C/W - Allows precise junction temperature estimation and reliable thermal margining when mounted to heatsink. |
| TJ(max) | +175°C - Supports operation in high-ambient environments (e.g., enclosed industrial drives, automotive under-hood). |
| iR (max) | 5.0 μA at VR = 400 V, TJ = 25°C - Ensures low standby power loss and stable blocking in high-impedance circuits. |
Pinout & Package
Package: TO-220AC (Case 221B), 3-pin outline with isolated tab (pin 3 = anode, pin 1 = cathode, pin 2 = NC). Mounting tab is electrically connected to cathode (pin 1) and serves as primary thermal path.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 | Cathode | Main current return path; electrically tied to metal tab for low-inductance, low-thermal-resistance mounting. |
| Pin 2 | Not Connected | No internal connection; must remain unconnected in PCB layout to avoid mechanical stress or shorting. |
| Pin 3 | Anode | Forward current input terminal; routed separately from cathode to minimize loop inductance in high-di/dt applications. |
Key Features
| Feature | Design Value |
|---|---|
| Ultrafast recovery (50 ns) | Reduces switching loss and EMI generation in >100 kHz SMPS, enabling smaller filter components and higher power density. |
| 175°C junction rating | Permits operation in thermally constrained enclosures without derating, improving system reliability in industrial and automotive environments. |
| Low VF (1.20 V @ 8 A/150°C) | Lowers conduction loss by ~15% vs. standard FRDs, directly improving efficiency in high-current output stages. |
| AEC-Q101 qualified (SUR8 prefix variant) | Validates robustness for automotive applications including engine control modules and onboard chargers requiring PPAP compliance. |
| Pb-free, RoHS-compliant | Meets global environmental regulations and enables compatibility with lead-free reflow soldering profiles (260°C/10 s). |
Applications
| Server PSU Rectification | Industrial Inverter Freewheeling |
|---|---|
Use Scenario: Secondary-side output rectification in 1–3 kW telecom/server switched-mode power supplies. IC Role / Device Role / Timing Role: Ultrafast power rectifier handling continuous 8 A DC output with high-frequency PWM switching. Use Value: 50 ns trr and 1.20 V VF reduce switching and conduction losses, enabling >94% efficiency and simplified thermal management. |
Use Scenario: Freewheeling path for IGBTs in 3-phase motor drives and UPS inverters. IC Role / Device Role / Timing Role: Clamp inductive kickback during IGBT turn-off with minimal voltage overshoot and ringing. Use Value: Soft recovery characteristic suppresses EMI, while 100 A IFSM withstands transient energy from motor back-EMF. |
| Automotive Onboard Charger (OBC) | High-Voltage DC Link Protection |
Use Scenario: Output rectification in bidirectional OBC AC/DC stage for EV charging systems. IC Role / Device Role / Timing Role: High-reliability rectifier rated for AEC-Q101 stress testing and 175°C ambient operation. Use Value: SUR8840G variant provides PPAP-capable supply chain traceability and extended lifetime under thermal cycling. |
Use Scenario: Reverse-polarity and overvoltage protection in 400 V battery management systems. IC Role / Device Role / Timing Role: Blocking diode preventing regenerative current flow into sensitive DC link capacitors. Use Value: 400 V VRRM and 5.0 μA leakage ensure stable isolation during long-term standby and fault conditions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar ultrafast rectifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| STTH8R04DJF | Same 400 V VRRM and 8 A IF(AV), but TO-220FP package (full-pak); RJC = 2.5°C/W; trr = 45 ns. | Lower profile package suits space-constrained layouts; slightly higher thermal resistance requires tighter heatsink design. | Preferred where board height is limited and footprint matches TO-220FP mounting holes. |
| IXYS MUR840E | Identical electrical specs (400 V, 8 A, 50 ns), but legacy Pb-based packaging; not RoHS-compliant; no AEC-Q101 certification. | Acceptable for legacy industrial designs without environmental or automotive compliance requirements. | Only for cost-sensitive, non-RoHS, non-automotive programs with existing MUR840E qualification data. |
Compared with MUR840G, STTH8R04DJF offers marginally faster recovery in a lower-profile package but trades off thermal performance, while IXYS MUR840E lacks RoHS and AEC-Q101 compliance - making MUR840G the optimal choice for new industrial and automotive designs requiring full regulatory alignment and thermal headroom.
Availability
MUR840G is available at Aetrix Electronics and suitable for switching power supplies, motor drive inverters, and automotive onboard chargers requiring stable component supply, long-term lifecycle support, and AEC-Q101 traceability.
Supply support for MUR840G 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
onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and IoT markets.
The MUR840G belongs to onsemi's Ultrafast Rectifier family, engineered specifically for high-frequency switching power conversion where low recovery loss, thermal resilience, and reliability under harsh conditions are critical.
FAQ
What is the maximum junction temperature rating for the MUR840G?
The MUR840G has a maximum operating junction temperature (TJ) of +175°C, verified per onsemi's datasheet absolute maximum ratings. This allows sustained operation in high-ambient environments such as enclosed industrial power supplies or under-hood automotive systems, provided thermal design maintains TJ ≤ 175°C using the specified RJC = 2.0°C/W and appropriate heatsinking. The MUR840G datasheet confirms this rating applies across the full voltage range (400 V VRRM) and current capability.
Is the MUR840G pin-compatible with other devices in the MUR8xxG series?
Yes, the MUR840G shares identical TO-220AC (Case 221B) mechanical dimensions, pinout (cathode-tab/anode configuration), and mounting interface with MUR810G through MUR860G. All variants use Style 1 marking (pin 1 = cathode, pin 3 = anode) and same thermal pad layout, enabling drop-in replacement across the family when voltage and current ratings align with circuit requirements. The MUR840G datasheet explicitly confirms this package uniformity in the ordering information table.
Does the MUR840G meet automotive qualification standards?
The MUR840G itself is not AEC-Q101 qualified; however, its automotive-grade counterpart SUR8840G - listed alongside it in the same datasheet row - is fully AEC-Q101 qualified and PPAP capable. Both share identical electrical and thermal specifications, with SUR8840G differentiated only by enhanced process controls and traceability for automotive applications. For automotive designs, SUR8840G is the designated qualified version of the MUR840G platform.
What is the typical forward voltage drop of the MUR840G at rated current?
The MUR840G exhibits a maximum instantaneous forward voltage (vF) of 1.20 V at IF = 8.0 A and TC = 150°C, per the Electrical Characteristics table. At room temperature (TC = 25°C), vF is 1.30 V under the same current. These values reflect actual conduction loss under real operating conditions and are critical for calculating efficiency and thermal rise in high-current rectifier stages. The MUR840G datasheet Figure 6 provides typical vF curves confirming this behavior across temperature and current.
How does the MUR840G's reverse recovery time compare to standard fast recovery diodes?
The MUR840G achieves a maximum reverse recovery time (trr) of 50 ns under IF = 1.0 A, di/dt = 50 A/μs - significantly faster than standard fast recovery diodes (typically 100–500 ns). This ultrafast recovery minimizes stored charge (Qrr) and associated switching losses, enabling efficient operation in high-frequency SMPS (>100 kHz) and reducing voltage spikes and EMI in inductive switching circuits. The MUR840G datasheet specifies this value in the Electrical Characteristics table and validates it across temperature and current conditions.
MUR840G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- SWITCHMODE™
- Package/Case:
- TO-220-2
- Packaging:
- Tube
- Product Status:
- Active
- Technology:
- Standard
- Voltage - DC Reverse (Vr) (Max):
- 400 V
- Current - Average Rectified (Io):
- 8A
- Voltage - Forward (Vf) (Max) @ If:
- 1.3 V @ 8 A
- Speed:
- Fast Recovery =< 500ns, > 200mA (Io)
- Reverse Recovery Time (trr):
- 60 ns
- Current - Reverse Leakage @ Vr:
- 10 µA @ 400 V
- Capacitance @ Vr, F:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-220-2
- Operating Temperature - Junction:
- -65°C ~ 175°C
MUR840G FAQ
1.How can I place an order for MUR840G through Aetrix?
Please submit a Request for Quotation (RFQ) for MUR840G on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for MUR840G reliable?
The price and inventory of MUR840G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MUR840G is usually 5 days.
3.What payment methods are accepted for MUR840G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MUR840G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MUR840G?
MUR840G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MUR840G order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for MUR840G?
For technical support, including MUR840G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MUR840G requirements.
6.How does Aetrix verify that MUR840G is sourced from the original manufacturer or authorized distributors?
All MUR840G products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MUR840G meets industry standards.
7.What is the process for return or replacement of MUR840G?
All MUR840G units undergo pre-shipment inspection (PSI). If there is an issue with MUR840G, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The MUR840G part is unused and in its original packaging.
Return procedure for MUR840G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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