What's good a sub picoamp op amplifier

LMC6001s are 100% tested for < 25 fA bias current. Which is probably why they are so expensive.

John

the set off.

potted).

contract / brightness / volume control TV

The neon is cute. The cap could have been in Miller config, better for linear control.

RCAs early small-signal mosfets had amazingly low leakage. I tried one as a source follower, and disconnected the gate, and was amazed to see that it just held the same source voltage. To measure the leakage, I put a small cap gate to ground and watched the source voltage drift millivolts per hour, and did the math.

John

Just the fact of putting a part through a handler charges them, i.e. sliding down the rail. Generally they jam an air ionizer near the handler, but that only does so much. So you short the pins with relays to get rid of built up charge, just to make the attempt at a test possible. I've seen DUT boards where they put in a 2nd relay with the current flow reverse (i.e. via pin out) supposed to get around built in potentials in the contacts.

I suspect they don't allow this kind of testing offshore, but don't know that for a fact. [Lots of BS happens in offshore test facilities, even if captive. You have managers trying to get bonus money, or what passes for engineers trying to look like they don't need help from the mainland.]

So...if you are making something using that and want to screw a competitor, AND have lotza bucks, just order tens of thousands every week and insist on delivery ASAP.. ..IOW guzzle the whole production.

And then offer the chips on spot market when the 'shortage' drives up the price, you think that's not happening?

Grant.

Fets are tricky.

Testing power mosfets is fun too. Expecially with a multimeter. If you charge the gate capasitance somehow, fet may always conduct and then suddenly stop conducting. If you are not careful, you can not decide is it broken or not. Or what is happening. If you are carefull, this can be used against them (the fets I mean). Working gate should hold it's charge and so on.

By the way, power fets. Has anyone made logic gates with them. Fets in logic ics and power fets are both enhancement type. 50 volt logic family sounds interesting.

Leif

Why not use

Just check off the parameters you need.

I can't see the field for "good" :)

They really should have one, it's what the public demand. They gave in on a sortable "prices" field so why not...

Good point, I go looking for the expected voltage drop of the substrate diode, assume handling all the pins shorts the gate charge out to source.

No thanks, I prefer my power circuits to be better guided, not doing the guiding, too easy to lose the magic smoke :)

Grant.

Connect the ohmmeter from drain to source.

Touch drain and gate. You should see conduction.

Touch source and gate. Should look open.

Both states should be stable for minutes at least, telling you the gate isn't leaky.

Or 800 volts!

John

The Holy Grail of parametric searching. It knows what you want even when you don't!

Probably find a good one here...

-- Many thanks,

Don Lancaster voice phone: (928)428-4073 Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552 rss:

Please visit my GURU's LAIR web site at