BJT base current 1/f noise

Am 17.02.2018 um 16:31 schrieb Kevin Aylward:

No. I didn't miss the point. The few parts that are suspects are worthy to be clicked upon. And then you see them in the right order when you scan the plot from top to bottom. And also who is the worst offender, at just one sight and at each & every frequency.

Not a table for each frequency that really nobody with a working brain wants to scan line by line.

(boring table snipped)

No.

Yeah. Me. The simulations and the product, too. Does an oscillator and the complete analog part of a Dual Mixer Time Difference system to compare two atomic clocks, a hydrogen maser and a cesium, count?

The flight sample had to work right after production, every change would have been an enormous paper work, and no solder joint to be heated more than 3 times. One change. Definitely. No place for adjusting the pulling range, and the crystals had been produced already.

The whole system does what JL's time distribution system does, only that one of the partners goes around the earth every 2 hours. Navigation on a mm scale. It is completely integrated by now, waiting for SpaceX to bring it to the space station.

There is nothing that contradicts my words that Spice is unable to perform nonlinear noise analysis. There has been a group of people on the LTspice list who wanted to force it. That has turned pretty silent.

And with your venom against Hajimiri-Lee you are standing quite alone. There are people who built on it with further developments. Rohde comes to mind.

Bla. Your small geometry MOS transistors, resonators with a Q like a wet sack of sand don't go together well with state of the art low noise oscillators. The idea of reducing 1/f noise by feedback is as old as 50 years, when some Russians discovered that a 33 Ohm emitter resistor can drop that by 20-30 dB. Was propagated by NIST then.

Now that Tina has made a belly landing at TI, isn't that THE opportunity for SS to fill the void? I mean, you seem to have connections to TI?

Cheers, Gerhard

(Please bear with me, I have to think in a foreign language.)

Ho hum.....

Was that more than the one?

Sure, Spice can't do phase noise. What's you point?

Err... No. I guess you missed the point that A. Demir mathematically

The reality is, if there is a non linear cap, HL fails. That means all practical circuits.

Do you have an academic reference that refutes A. Demir to support that your claim that he is wrong? This would be interesting indeed, as A. Demir's method is the method used by Berkley Design Systems, bought by Mentor.

I guess you don't understand the difference between a theory that is an approximation under known conditions, say Newton gravity compared to General Relativity, and one that just happens to give the right answers by luck, like Phlogiston does for fire.

A theory like a stopped watched being accurate at two time points per day, is wrong. Period.

Name a commercial simulator that actually uses the HL technique...

I have no idea as to what you are referring to here. I design commercial, precision xtal ocxos and tcxos asics with Qs of 100,000s. They have ppb temperature stability.

hint:

In general, local feedback does not reduce 1/f noise. The claims that say they do, are in general, false. The basic reason is that there is no feedback when the oscillator is limiting. You need to compare apples with apples. None of the papers I have seen that claimed feedback reduced noise actually did a proper A B test. Most papers are confused. I have run many tests on claimed designs where the actual feedback bit was engaged or not engaged with the circuit otherwise staying the same, and nothing changed noise wise.

My paper here illustrates one example where the authors, essentially, claimed it was feedback, but they were mistaken.

-- Kevin Aylward

Careful, Kevin! Being right around here garners you enemies who will proceed to make it their lifetime goal to bury you in vituperatives ;-)

Just look at the s*it I have to endure just from pointing out what a piece-a-crap LTspice is.

But I know we'll both hang in there... it's _such_ fun kicking idiot's asses >:-} ...Jim Thompson

You have other faults, and most of the s*it directed at you isn't prompted by your dislike of LTSpice.

But in quite a few areas Jim presents himself as an ill-informed ass who whose backside needs kicking.

His uncritical acceptance of the nonsense that gets published on HotAir and TownHall is evidence of intellectual incompetence, and his passion for posting links to some of it on an electronics user group demonstrates regrettably poor judgement.

You must be pretty badly bruised up by now.

It's the twilight zone. I can understand that many might just accept what they are spoon fed from their Masters, but once obvious flaws are pointed out, why people defend the indefensible, is pretty stunning.

In the case here, without even understanding the somewhat complex math of the A. Demir paper (on my site) , a basic understanding of electronics trivially refute HL.

It will be a sad day for all of us, when you are no longer here to hung on in, Jim. Age is the final master of as all.

-- Kevin Aylward

Yep. It keeps trying to get me, but I keeps fighting back... I'm not done yet >:-}

I was just musing last night, whilst sipping Kim Crawford Sauvignon Blanc and watching the figure skating competitions... I'm coming up on the 48th year since I first started using Spice... so I see no problem becoming expert in LTspice within a week or two ;-)

Then I can address bloviators with, "Ehhhh! Really?" ...Jim Thompson