Interesting curves...

How annoying. No Idss spec, no DC curves. RF people are like that: just fiddle with the bias until it works.

Since the abs max range of gate voltage is -8 to -2, it's presumably destroyed in shipping. Unless they ship it with a battery attached.

Abs max supply voltage is 48, but leakage is tested at 175.

The forward transconductance spec is clearly wrong.

Pitiful. We use phemts in pulsed time-domain applications, and usually have to test them ourselves to get basic specs. Even the manufacturers often don't know basic stuff about their parts. A Spice model, or even basic DC curves, is rare for RF parts.

Well, it is clear why. However the one who prepares datasheet doesn't seem to have a clue.

VLV

Which is another job idea: offer to proof-read peoples's data sheets. That would be the ideal job for some older guy who knows everything about everything.

John Larkin furthers his claim to be our most out-of-touch-with- reality poster.

I've never made any claim to be particularly expert with RF parts. I've certainly used wide-band transistors at frequencies close to

Don't feel bad, the other day I discovered that we have a tube of power mosfets 18 amps, 500V out of a batch we order with a different date code on them that does not pass the 500V break down test, they're good for only ~250v before they start to break down. These were purchased all at the same time but this particular tube seems to be older stock.

Not only that, I notice the package, although the same type, looks like they were made else where on the planet, they don't seem to have the same exact mold shape. I wonder if I got rebranded or defective parts?

It's not a bug deal, we just put those assigned with a note on them, they now are test fets, but these fets are not cheap and it's a good thing I didn't pay for them..

Jamie

I keep making great suggestions about fun and useful things that geezers could do, and geezers pop up and tell me what they don't know and can't do.

Vladimir Vassilevsky a écrit :

I meant the small hook at the curves upper right extremity.

I'd be curious to know what so obvious about these...

On the previous plot, they have output power vs input power. The output power decreases after passing maximum due to overexitation. They just put sequential numbers of the output power from that plot into drain efficiency calculation. So, after maximum reaching maximum power, the graph makes a hook.

Vladimir Vassilevsky DSP and Mixed Signal Consultant

Something wrong . . look carefully at the last graph on page 4. One cannot have _two_ efficiencies at a given output power.

Something wrong . . look carefully at the last graph on page 4. One cannot have _two_ efficiencies at a given output power.

Maybe counterfeit parts..a lot of that going on.

Maybe they were shot down by those big companies that need expertise. HR takes one look at them and instantly determine they are 40 or older and kick them out as being "overqualified". The companies would rather hire two greenies fresh out of college and $$pend even more money in training for a year or so to get them to be useful..

Absurd. It's just the opposite, in fact. Recent grads are living in mommy's basement, playing the XBox.

It's the contrast between ill-informed fantasies and objective reality. The US electorate seems to have preferred the latter.

It doesn't pay.

A typo in the hand is worth two proofs in the bush.

RL

Sure you can. There's nothing inherent in the idea of an amplifier that prevents the output power from going down as you increase the input power, past a certain point. All you need is a bias shift.

Cheers

Phil Hobbs

Can't blame the spreadsheet software.....

Actually, Excel used efficiency as the dependant coordinate for drawing the line connection sequence. Efficiency should drop with over-exitation, if input drive power is included in total power consumed.

There are valid bistable graphical plots, but this isn't one.

RL

You'd make a perfect politician, never getting the facts right and always twisting the truth, if you really knew what the truth was.

Jamie