2N7002

Wussy! The curves only go to 100 mA; the 2N7002 curves go to 2 amps.

The Id/Cg ratio of the 2N7002 is maybe 6x better.

Everything gets integrated, so discretes go away.

--

John Larkin         Highland Technology, Inc 
picosecond timing   precision measurement  

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com

The RUM001L02 part's Ciss is 7pF vs 30pF for 2n7002 at 5V, and it does 0.25A reasonably well. Crss 2 vs 10pF. 3-ohms at 2.5V, 6-ohms at 1.2V. SOT-723 seems an impossibly-small package, but its 0.8mm pin spacing is fine for hand soldering. It absolutely has a legitimate place in our small-part lexicon, thanks Tim. Also check out the SOT-723 p-channel RZM001P02.

--
 Thanks, 
    - Win

Just make everything out of LM324s, lol they've been cranking out billions of those dumpy ol' things a year since Moses was a baby and will be 'till Judgment Day.

This is fun:

Gate leakage is not many electrons per second. You can transfer charge in and out of the open gate with a small insulated screwdriver (carry bits of charge from Vcc or ground) and ratchet the LED brightness. Briefly connect drain to gate to turn it halfway on.

--

John Larkin         Highland Technology, Inc 

lunatic fringe electronics

it

Since 1972, to be more precise. The uA702 came out in 1964, and the uA709 i n 1965. I paid $30 for a uA709 in Australia in about 1967.

The LM324 is actually pretty horrible, but it's cheap and works well enough to do a great many undemanding jobs. I wrote an op amp standard at Cambrid ge Instruments around 1988, which listed some 150 op amps, which did includ e the LM324/LM358 as useful and widely available from many sources, if chea p and nasty.

--
Bill Sloman, Sydney

I use a fair number of LM358s for stuff like bias loops and current limiters. The genuine TI TLV272s are good for undemanding high-Z stuff, but the Diodes ones are shockingly noisy.

My fave general-purpose jellybean is the MC33078 dual--4.5 nV noise, 15 MHz, 7 V/us. Its input bias current is on the high side, of course, but at the price it can't be beaten.

Cheers

Korg sells these little "Monotron" pocket analog synthesizers with a ribbon controller that a lot of synthesizer dudes/bedroom musos like to play with, guess they've sold a lot of them:

Inside it's just a little boost converter chip to create +5/-5 rails from the two AA batteries, couple LM324s for sawtooth integrators/exponential converter current source/VCA/audio preamp, and an 8 pin class D audio output chip. Sounds cool and retro but its line out is pretty noisy, too.

I doubt they would've hit the power consumption and $49 price target using any other IC.

My employer, Nexperia, is currently investing millions to upgrade its 200mm Hamburg waferfab (which up to last year did only bipolar) just to crank out more 7002s. The process has its flaws and was projected to be retired four development generations ago, but it's still going full steam. No worries, the 7002 is there to stay.

robert

Good news; thanks.

It's shocking that you can buy a mosfet this good for three cents.

I bet you get a lot of them per 200mm wafer.

I sure wish people wouldn't keep killing off the fast bipolars, like BFQ149.

--

John Larkin         Highland Technology, Inc 

lunatic fringe electronics

We get them a lot lower than 3 cents, use them where possible

Three cents? I get them for 1 US cent or less from AliExpress. Like, at present, -

or

I know that many people distrust cheap materials sourced from China, probably with good reason. Personally, circumstances force me to depend more and more on AliExpress in recent years. So far, the only time I've ever had a problem with parts from AliExpress was with a batch of leaky CMOS gates that didn't behave well in a high-impedance circuit.

I've been using their 2N7002 successfully in non-critical applications. I wish someone would test them more thoroughly and share the results.

you're probably getting the remnants left after someone else's production run, if the parts haven't been mistreated all should be well.

--
This email has not been checked by half-arsed antivirus software

It's hard to imagine how they could cheapen 2N7002s, though they're ingenious and always find some way.

Be interesting to see statistics on Rds(on), Vds(max), Vgs(th), Ciss and Coss.

Tim

--
Seven Transistor Labs, LLC 
Electrical Engineering Consultation and Contract Design 
Website: https://www.seventransistorlabs.com/

The max. threshold voltage is somewhat high, 2.5V. BTW, the problem is to find small transistors with *high* C_GS. I needed one for a fast, passive gate turn-off circuit. It took ~2 hours to find AO3407, which has all the desired properties.

Best regards, Piotr

I've just bought several LTC parts at half the price. Everything I can check is fine, but they weren't the cheapest offer. An acceptable source for one-offs.

Best regards, Piotr

They're amazing. A diligent search often turns up a single

10-cent product offered with free shipping. I once ordered a microSD card reader at that price, just to see if it's real. It was, and it works fine.

I'll see if I can find time to test some of the more important characteristics over the next few days.

0mm

out

ur

,

more like 1 cent

We have some part bins that specify a 2N7002 from a specific manufacturer. They can be different.

We'd never buy production parts from China, or from a broker. Only known suppliers from authorized distributors.

--

John Larkin         Highland Technology, Inc 

lunatic fringe electronics

That's why you pay more. I wouldn't rely on parts from China for production either but for other purposes, not everyone can afford to pay premium prices.

Parts for production spread over a narrower range of types, are usually bought in quantity and can be sourced from manufacturers and their distributors even here in India.

I've mentioned in other threads that there are practically no online retail sources of parts in India. The two exceptions are RS and Farnell/element14 but they require tax registration to even register at their site. They openly declare that their target market is OEMs and do not care to have individuals as customers.

It's not unusual for these two giants to set prices at literally

3 to 50 times those at physical shops even before the influx of Chinese parts. Frankly, I don't know how they've have managed to survive. I must be missing something.