[Top] [All Lists]

Re: [Amps] LDMOSFET input impedance

To: Manfred Mornhinweg <>
Subject: Re: [Amps] LDMOSFET input impedance
From: jeff millar <>
Date: Fri, 2 Feb 2018 01:34:31 -0500
List-post: <>
I don't exactly know, but it's almost pure capacitance.  As a starting
point, on the order of 1000 pF.  All those FET's have the same basic
design, so if you find a similar transistor from the same manufacturer that
has data for lower frequencies, that should provide a hint.  The power and
capacitance should scale together. because all the parts of a family have
the same voltage swing and just vary in current rating and the number of
mini FETs in parallel within the die.

The trick is to generate enough voltage across that much capacitance to
switch the FET.

jeff, wa1hco

On Sat, Jan 27, 2018 at 5:59 PM, Manfred Mornhinweg <>

> Hello,
> does anybody have any data about the input impedance of the MRF1K50N or
> any other broadly comparable LDMOSFET, at 30MHz and possibly below?
> The datasheets typically only give this data for some VHF frequency.
> Manfred
> ========================
> Visit my hobby homepage!
> ========================
> _______________________________________________
> Amps mailing list
Amps mailing list

<Prev in Thread] Current Thread [Next in Thread>
  • Re: [Amps] LDMOSFET input impedance, jeff millar <=