Toshiba 40V MOSFET Cuts Losses In Power Supplies

Low-voltage power stages are not simple anymore. In data center rails, industrial DC-DC converters, and high-current regulators, small gains in conduction loss and switching behavior now carry more weight than they used to. Toshiba’s new TPHR6704RL is a 40V N-channel power MOSFET built on the company’s latest U-MOS11-H process, intended for power designs where lower loss and cleaner switching both matter.

The TPHR6704RL is a 40V N-channel power MOSFET used in switched-mode power supplies, DC-DC converters, switching regulators, and motor drivers. In a typical server or industrial power rail, that means it sits in a switching path where RDS(ON), gate charge, and parasitic behavior directly affect heat, efficiency, and how hard the rest of the layout has to work. Toshiba specifies a typical RDS(ON) of 0.52mΩ at 10V gate drive, with a maximum of 0.67mΩ at the same condition.

U-MOS11-H Pushes The Switching Tradeoff Further

The resistance drop is the obvious headline, but the more useful detail is the figure-of-merit improvement. Toshiba compares the TPHR6704RL against its earlier 40V TPHR8504PL built on the U-MOS IX-H process and says the new part reduces RDS(ON) by about 21%. With a typical total gate charge of 88nC and a gate switch charge of 24nC, Toshiba also claims roughly a 37% improvement in the RDS(ON) × Qg figure of merit. That is the part power designers will care about, because low resistance only goes so far if the switching penalty climbs with it.

In real converters, that tradeoff shows up as switching loss, thermal load, and how much design margin is left once current density starts rising. That is where better silicon stops being a marketing number and starts affecting the whole power stage.

Lower Spike Behavior Matters Too

Toshiba also says the TPHR6704RL helps reduce EMI by minimizing drain-source voltage spikes during switching. That may end up being just as useful as the lower milliohm number. A MOSFET can look efficient on paper and still create extra cleanup work through ringing, overshoot, and switching noise that leaks into the rest of the system. In dense DC-DC designs and data center power rails, that kind of behavior gets noticed quickly.

A Practical Upgrade Path For Existing Designs

Toshiba rates the device for up to 420A drain current, with a channel-to-case thermal resistance of 0.71°C/W at 25°C and a maximum channel temperature of 175°C. The device is housed in Toshiba’s SOP Advance (N) package and is footprint-compatible with existing SOP Advance designs, which gives engineers a more practical upgrade path than a part that forces a board-level redesign.

What makes the TPHR6704RL worth watching is not just that it is another low-resistance 40V MOSFET. It is that Toshiba is pushing on the part of the design space where conduction loss, switching charge, EMI behavior, and thermal pressure all start arguing with each other at once. That is usually where the useful parts show up.

Learn more and read the original announcement at www.toshiba.semicon-storage.com

Technology Overview

The TPHR6704RL is a 40V N-channel power MOSFET fabricated using Toshiba’s U-MOS11-H process for switched-mode power supplies, DC-DC converters, switching regulators, and motor drivers. Toshiba specifies a typical RDS(ON) of 0.52mΩ at VGS = 10V, a maximum of 0.67mΩ at VGS = 10V, and a typical total gate charge of 88nC.

View the TPHR6704RL datasheet.

Frequently Asked Questions

What is the TPHR6704RL used for?

It is used in switched-mode power supplies, industrial DC-DC converters, switching voltage regulators, and motor driver circuits.

How does the TPHR6704RL improve efficiency?

Toshiba says the device lowers RDS(ON) by about 21% versus the TPHR8504PL and improves the RDS(ON) × Qg figure of merit by about 37%, helping reduce loss during switching operation.