Teardown: Delta DPS-1600AB-37 A 1600W CRPS Server PSU — Toshiba TK31N60X MOSFETs in the PFC Boost Stage
2026-09-23 · Compiled by Best IT Parts from public industry reporting
A teardown of the Delta DPS-1600AB-37 A, a 1600W server power supply in the standard CRPS form factor, shows a PFC boost stage built around two Toshiba TK31N60X N-channel MOSFETs mounted side by side on the main heatsink. The unit has a cooling fan and an IEC inlet on the outer face and a gold-finger connector on the inner side for the server connection.
Output ratings depend on input: 1000W maximum with a 12V/83A main rail at 100-120V AC, rising to 1600W with a 12V/132A main rail at 200-240V AC or 240V DC, alongside a 12V/2.1A standby output. The supply uses a PFC plus half-bridge LLC plus synchronous rectification architecture with silicon carbide Schottky diodes in the PFC rectifier. The TK31N60X is the PFC boost main switch, gated directly by an STMicroelectronics PM8834 dual low-side driver; the shared heatsink also carries the LLC switches and is the highest heat-flux area on the board.
The TK31N60X is a 600V superjunction device from Toshiba's DTMOS-H series in a TO-247 package. Ratings include 30.8A continuous drain current, 123A pulsed, 73mΩ typical and 88mΩ maximum on-resistance, ±30V gate-source voltage, a 2.5-3.5V gate threshold, 3000pF input capacitance, 70pF output capacitance, 7pF reverse transfer capacitance, 1.8Ω gate resistance and 65nC total gate charge split into 19nC gate-source and 22nC gate-drain. Body diode reverse recovery is 410ns with 3.5µC recovery charge, diode dv/dt tolerance is 15V/ns, device dv/dt is 50V/ns, and the channel is rated to 150°C.
The TO-247 package routes the drain to a copper baseplate so the device can be screw-clamped to the heatsink, matching its 230W allowable dissipation and 0.543°C/W junction-to-case thermal resistance. In this position the balance between 73mΩ on-resistance, 30.8A current handling, 3000pF input capacitance and 65nC gate charge keeps conduction and switching losses controlled across a wide input range.
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Technical details are reproduced as reported. Verify specifications against the original source before design or procurement decisions.