SRT045N012H Low-Voltage Power MOSFET PDFN5 - ASIC Hashboard repair

SRT045N012H 45V Power MOSFET for ASIC Hashboard Buck Stages

The SRT045N012H is a low-voltage N-channel power MOSFET in a PDFN5x6 surface-mount package, engineered for high power density and synchronous rectification. With a 45V breakdown, low on-resistance and ultra-low gate charge, it is well suited to ASIC miner hashboard buck converters, PSU secondary-side synchronous rectifiers and high-current DC/DC stages.

On modern hashboards, dozens of low-voltage MOSFETs operate in parallel to step the PSU rail down to the chip core voltage. When one fails short, the affected chain drops out, the board overdraws current or the PSU triggers OCP — replacing the burned FET (and checking its driver and gate resistor) is the standard repair path.

Specifications

Application in ASIC miner repair

On Antminer and Whatsminer hashboards the PSU 12V/15V/21V rail is stepped down to ~0.4–0.8V chip core voltage through multi-phase buck converters. Each phase pairs a high-side and a low-side MOSFET driven by a dedicated controller. The SRT045N012H fits in this low-side / synchronous-rectifier role, where its low Rds(on) and low Qg minimize conduction and switching losses across the kilowatt-level current flowing into the ASIC array.

Failure on this stage almost always shows up as one or more shorted FETs around a chip group. The classic signature is a localized burn mark, a dead chain on the board test report, and the PSU latching off after a few seconds. Always replace the failed FET, check its gate driver, gate resistor and the inductor leg before powering the board back up.

Compatibility / Where it fits

Found across hashboard buck stages on modern SHA-256 and Scrypt miners, PSU secondary synchronous rectifiers, and the 12V auxiliary DC/DC sections on control boards. Always cross-check the original part marking, package footprint and pinout before substituting — PDFN5x6 has many electrically similar but mechanically incompatible siblings.

Common failure symptoms

• Hashboard hashrate drop or full chain dead on a specific group of chips
• PSU triggers OCP or shuts down within seconds of start-up
• Localized burn mark, cracked package or discolored solder on a PDFN5x6 position
• Board test reports core voltage out of range on one phase
• Repeat failures on the same phase suggest driver or gate-resistor damage too

Frequently asked questions

Can I replace just one MOSFET in a multi-phase buck stage?

Yes, but verify the matching FET on the opposite (high-side or low-side) position is healthy. Mismatched on-resistance between phases unbalances current sharing and shortens the lifespan of the replacement.

Why does the PSU trip immediately after I install a new FET?

Most often the gate driver, gate resistor or bootstrap capacitor of that phase was also damaged. Probe the driver output, check the gate resistor for open/short, and confirm the bootstrap cap before reapplying full load.

Do you ship reels for fleet repair?

Yes. Contact us with the quantity and we will quote cut-tape, partial reel or full-reel pricing.

Is the SRT045N012H suitable for the high-side position?

The SRT045N012H is optimized for synchronous rectification (low-side) and DC/DC applications where ultra-low Rds(on) and Qg matter most. The high-side position usually uses a different optimization point — check the original board layout before swapping roles.

Related products

• NTMFS5C430NL MOSFET for Cryptominer Hashboards
• IPW65R029CFD7 MOSFET for Whatsminer PSU
• MD18623 Gate Driver for Dual MOSFET
• ISL99360FRZ Antminer Z15 Driver
• K8 Universal Hashboard & PSU Tester

Contact contact@lys-sz.com for volume pricing or compatibility questions.

Worldwide shipping from our Shenzhen warehouses, DDP available for US and EU customers.