# Information on high frequency switch mode power supply

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#### fasaghandis

##### Member level 5
Dear friends
May you provide me information on high frequency switch mode power supply.
Is distributted element used for the construction of them.
Is there commecial transistors and Mosfet for this type of SMPS

#### v_c

Re: high frequency SMPS

There are commercial applications in the 1MHz range and other specialized applications in the 100MHz range. Just Google and you will find plenty of application notes and datasheets for the controller ICs and MOSFETs for the commercial applications.

#### fasaghandis

##### Member level 5
Re: high frequency SMPS

Dear v_c
Just help me to find a datasheet for a comercial mosfet, operates in frequency higher than 1MHz

#### fasaghandis

##### Member level 5
Re: high frequency SMPS

www.smpsus.com do not work. Please note that I want part number of mosfet that work at high frequency(upper than 1MHz)
Regards

#### v_c

Re: high frequency SMPS

Here's something from the STMicroelectronics web site
ST has introduced a new state-of-the-art technology tailored to the high-side function in DC-DC converters. This new STripFET III process, (internally known as “SP3”), utilizes the latest generation of ST’s planar technology and is optimized for high switching frequency applications, even up to 700kHz and 1MHz.
This technology shows excellent dynamic performance in conjunction with optimized packages. It is possible to reach very good static behaviour, obtaining a figure of merit, RDS(on) * Qg, below 100mOhm * nC in an SO-8 package.

Here's the product range -- take a look at the datasheets.

http://www.st.com/stonline/stappl/productcatalog/app?path=/comp/stcom/PcStComOnLineQuery.showresult&querytype=view=table$$type=product$$Parametric=Y&querycriteria=RNP139=76XJE010^VT-007=ST*NH*

Note that at high frequencies you have to watch the parasitic components of the MOSFET carefully.
For example, the discharging of the MOSFET output capacitance in the turn-on
transition causes a loss proportional to $C_{oss} V_{ds}^2 f_{sw}$ --
so higher switching frequency means a higher switching loss. Using ZVS (zero-voltage switching will help this). Just google on this for more information.

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### fasaghandis

Points: 2

#### fasaghandis

##### Member level 5
Re: high frequency SMPS

Dear v_c
Have you any experiences in this regard. May you inform the best mosfet for this purpose
regard

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