New MOSFETs

Siliconix recently announced the industry's first n-channel MOSFETs that combine a high 3.4-V threshold voltage with on-resistance as low as 2.7 milliohms.

The 10 new MOSFETs, available in 40-V and 60-V versions, are intended for use in high-temperature, high-current applications with inductive loads in the automotive, industrial, and fixed telecom industries, such as high-side switches, motor drives, and 12-V boardnets.

When MOSFETs operate in high-temperature, high-current environments, they can turn on spontaneously if their threshold voltage, impacted by heat, starts to approach 0 V.

Until now, this posed a dilemma for designers. One solution was the addition of a negative voltage driver to the circuit, but the drawbacks were increased circuit size, cost, and complexity. Another solution would be to use a device with a high threshold voltage, but the effect in this case is an undesirable increase in on-resistance.

This new power MOSFET family provides a way out of this dilemma with high-density silicon technology that allows the same device to deliver both low on-resistance and a high threshold voltage that avoids the problem of spontaneous turn-on in automotive, industrial, and other applications involving high temperatures and high levels of current.