• You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.

Silicon Carbide MOSFETs?

nomadradio

Analog Retentive
Apr 3, 2005
7,001
11,189
698
Louisville, KY
www.nomadradio.com
So, who's gonna be the first to try some of these as RF amplifiers?

SiC MOSFET transistors are the next big thing in power-supply design. The one in the data sheet below is meant for pretty high voltages.

But the capacitances look really low, and the switching speeds pretty high.

Haven't even checked the price, yet.



Looks kinda promising.

73
 

Attachments

  • LSIC1MO170E1000_DS.pdf
    1,016.7 KB · Views: 21

gate voltage shows typ 2.5 and max 4.0 which does not look bad but the size shows it to be a T0 247. a little large for a final for most radios unless I am missing some thing in looking at the spec sheet.
 
some pics from that project:
cree_rig_front.jpg


cree_rig_side.jpg


cree_rig_closeup.jpg


LC
 
  • Like
Reactions: Shadetree Mechanic
Albeit the size could it be used to replace a 2sc1969?

I am not the master techs you's guys is. I just have a POS 148gtl needs attention and resourcing is all I can do. I follow you's guys trying to learn. Though I am in the weeds I have benefited with knowledge from this place.
 
  • Like
Reactions: Shadetree Mechanic
redbeard,

your best bet for repairing that final is to either buy a real 2SC1969 or you can convert it to an IRF520 mosfet.

exit13 wrote up an excellent article on how to convert the old school 8719 and 858 radios to mosfets.

it's here on the forum somewhere.
LC
 
Although you have a working prototype, that's great, but remember the issue of "carbon" doping versus the other elements like Boron or Gallium - Hole - Donor principle.

They make the part able to be "shut off".

Carbon doesn't have the graces of having that property.

It wants to keep the part "on" all the time - electrons will have no where to fill in what's left - they have to wander across to find equilibrium.

What is worse is there lack of rectification ability without forming a PN junction to form a barrier to make this work.

It's the "fall times" that make this worrisome for making Amps work without generating a meltdown similar to what the Fukushima plant experienced.

Now, before anyone screams - "The do it with LED" - remember that the junction itself is what emits the radiation - as you work thru the process you'll see that making Diamonds in the lab is a far easier way to make money than to re-create that which was formed in nature on a more gradual - volcanic - way using Oxygen, Sulfur or Nitrogen to generate the various effects as catalysts on the two materials.

But, "As Seen On You Tube" - they're working on it.
 
  • Like
Reactions: Shadetree Mechanic
Pretty sure the amp in the pic above is for 7 MHz. All switchmode MOSFETs will have an upper frequency limit. The bigger the part, the lower that frequency tends to be.

The numbers to watch in the specs are rise time, fall time, turn-on time and turn-off time. Faster is better. Means a higher max frequency.

The Littelfuse part in the spec sheet above is faster than the specs shown for the IRF520.

That was what got my attention.

73
 

dxChat
Help Users
  • No one is chatting at the moment.
  • @ Wildcat27:
    Hello I have a old school 2950 receives great on all modes and transmits great on AM but no transmit on SSB. Does anyone have any idea?
  • @ ButtFuzz:
    Good evening from Sunny Salem! What’s shaking?