WSD20L70DN 20V 70A P-Channel MOSFET for Synchronous Buck Converters

WSD20L70DN P-Channel MOSFET | 20V / 70A High-Density Trench Replacement for Synchronous Buck Converters

The WSD20L70DN is a 20V / 70A P-channel power MOSFET in a compact DFN3×3-8 package, built with high cell density trench technology for low RDS(on) and gate charge. Used as the high-side switch in synchronous buck converters on hashboard / control-board power conversion stages where switching frequency and conduction losses both drive efficiency.

Headline numbers for synchronous buck duty: 7.9mΩ maximum RDS(on), 70nC total gate charge, 927pF drain-source capacitance, 52ns rise time, and excellent CdV/dt attenuation for stable operation under fast-switching transients. Max junction temperature 150°C with 83W power dissipation envelope — covers the realistic operating window for ASIC miner buck converters.

When to Replace the WSD20L70DN

• Synchronous buck output dead — high-side MOSFET shorted or open after a fault event.
• Excessive heat on the MOSFET at normal load — RDS(on) drifted, conduction losses climbing.
• Visible damage on the DFN package — cracking, blackening after a downstream short event.
• Buck output ripple climbing — degraded MOSFET switching characteristics, switching losses up.
• Adjacent gate driver also failed — voltage spike from a shorted MOSFET often kills the driver in the same event.

WSD20L70DN Specifications

FAQ — WSD20L70DN P-MOSFET

Q: How do I confirm the MOSFET is the dead part?
A: Power off. DMM diode-test mode source-to-drain — healthy reads ~0.5–0.7V (body diode), OL the other direction. Shorted reads 0Ω both directions. Open reads OL both directions. With power on, scope the gate and drain waveforms: clean switching = healthy, distorted or shoot-through = degraded.

Q: Replace in pairs on a synchronous buck bridge?
A: Yes — when the buck uses a synchronous topology with high-side + low-side MOSFETs, replace in matched pairs to keep RDS(on) and Qg balanced. A single new MOSFET paired with an aged partner mismatches switching characteristics and stresses both devices unevenly.

Q: Always check the gate driver when this MOSFET fails?
A: Strongly recommended. Voltage spikes from a shorting MOSFET often take out the driver in the same event. Skipping the driver inspection is the most common cause of repeat failure within hours of the repair.

Q: DFN3×3-8 rework profile?
A: DFN packages have a center thermal pad that must reflow correctly. Bottom-side preheat 130–150°C, top-side hot air 320°C with flux paste. After reflow, X-ray inspection or AOI is the only reliable way to confirm the center pad joined. Hand-soldering is not suitable for DFN packages.

Q: Bulk pricing for repair benches?
A: Yes — email contact@lys-sz.com for reel-quantity WSD20L70DN pricing and matched gate-driver kits.

Related products

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• 2N7002 60V/115mA N-MOSFET (Antminer hashboard)
• DMP34M4SPS 30V/34A P-MOSFET (Antminer S11 / S15 / T15)
• AO3423 ASFA P-MOSFET 20V/2A (Whatsminer CB2 V8)

Repair benches stocking WSD20L70DN P-MOSFETs by the reel? Email contact@lys-sz.com for bulk pricing. Worldwide shipping from our Shenzhen warehouse.