WMJ80N65F2 650V N-Channel MOSFET | Charge-Balance Power Transistor for ASIC Miner PSU Repair
The WMJ80N65F2 is a 650V N-Channel power MOSFET built on charge-balance technology for low RDS(on) and low gate-charge performance — the kind of device used as the primary-side switching MOSFET on ASIC miner power supplies. Charge-balance / super-junction architecture is what allows 650V breakdown at low on-resistance — the standard trade-off for modern PSU switching duties.
Headline specs: VDS 650V @ Tj.max, typical RDS(on) 0.033Ω (33mΩ), 100% UIS-tested. The combination of high breakdown voltage and low on-resistance gives excellent thermal margin in continuous mining-PSU duty.
When to Replace the WMJ80N65F2
PSU fails to start — no DC output, primary switching dead.
Hiccup mode — PSU pulses on/off without latching to full operation.
Visible damage — burnt or cracked MOSFET package on the heatsink.
Multimeter shows shorted drain-source.
WMJ80N65F2 Specifications
Parameter
Specification
Type
N-Channel Power MOSFET
Technology
Charge Balance (Super Junction)
VDS (Drain-Source Voltage)
650V @ Tj.max
RDS(on) typical
0.033Ω (33mΩ)
Avalanche Testing
100% UIS-tested
Application
ASIC Miner PSU primary-side, LED lighting, charger / adapter, server
Package
MPT-3 / TO-220 variants
FAQ — WMJ80N65F2 MOSFET
Q: How do I confirm the WMJ80N65F2 is the failed part? A: Power off and discharge PSU bulk caps. Multimeter in diode-test mode across drain-source: healthy super-junction MOSFET shows OL one way, ~0.5V body-diode drop the other. Shorted = ~0V both ways; open = OL both ways.
Q: Substitute with another 650V super-junction MOSFET? A: Possible if RDS(on), Qg, and package footprint all match. Mismatched parts increase switching loss and trip thermal protection.
Q: Rework profile? A: Match the package — MPT-3 = hot-air SMD rework at 350°C with controlled airflow; TO-220 = through-hole rework with vacuum desoldering pump. Apply fresh thermal compound on through-hole variants.
ASIC PSU repair benches stocking WMJ80N65F2 MOSFETs in volume? Email contact@lys-sz.com for bulk pricing. Worldwide shipping from our Shenzhen warehouse.
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🇺🇸🇪🇺 USA & European Union (DDP): Orders are delivered DDP. All customs duties, import taxes, and fees are included — no additional charges on delivery.
🌍 Rest of world: Orders ship from China. Depending on your country, local customs authorities may apply import duties or taxes.
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