MERAKI MD18617 Gate Driver Drives PFC Stage in 2700W Platinum Server PSU: 4A Source/Sink, 11ns Delay
2026-10-10 · Compiled by Best IT Parts from public industry reporting
A teardown shows the MERAKI MD18617 high-frequency single-channel low-side gate driver used to drive the PFC switching transistor in a 2700W 80PLUS Platinum server power supply, model AH-CRPS2700A1M. The unit accepts 100-127V and 200-240V AC input plus a 240V DC input, with a rated 12.2V/221.4A output and a 2700W maximum rating. It is built on a PFC plus full-bridge LLC and synchronous rectification topology. The MD18617 sits on the rear of the PCBA in the PFC power-stage area, converting the controller's PWM signal into a gate-drive signal with sufficient current to rapidly charge and discharge the MOSFET gate.
Gate-drive strength matters at this power level. If drive current is insufficient, MOSFET turn-on and turn-off times lengthen, increasing the time spent in the high-voltage, high-current overlap region and raising PFC switching loss and device heating. The MD18617 is specified for N-channel MOSFET, IGBT and GaN devices, with a 4.5-26V supply range, up to 1MHz maximum operating frequency, and 4A peak source and 4A peak sink current in a SOT23-5 package.
With a 2.2nF load, the part lists rise and fall times below 10ns and a typical propagation delay of only 11ns, so it can follow the PFC controller's PWM output quickly. Its input withstands -7V to 28V, and the input logic threshold is independent of the VDD rail while remaining TTL and CMOS compatible. The negative-input tolerance targets ringing from gate transformers and long-trace parasitic inductance, improving noise immunity in high-frequency switching environments. The device also integrates undervoltage lockout: when the driver supply falls below threshold, the output stays low to prevent abnormal conduction of the power device.
For B2B buyers sourcing server PSU spares, the design reflects how kilowatt-class supplies depend on high-current gate drivers to keep PFC stages switching cleanly and efficiently.
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Technical details are reproduced as reported. Verify specifications against the original source before design or procurement decisions.