PMOS Equivalent to 2N7000?

Look at TP0610.

John

Also look at ZVP3306 and ZVP2106A.

Sometimes the BSS84 is used. At least by yours truly because they are under 5c in qties :-)

I've been using the Diodes DMG1012 (N) and DMG1013 (P), and am in the process of designing in the DMG1024 and DMG1023 (duals). They're in the area of $.05/transistor and SOT-523 is a nice package. ;-)

Just make sure the duals have a 2nd source :-)

Or buy enough the first time. ;-)

For small runs, yes. Inventory is majorly frowned upon by the financial folks and can also have bad tax consequences unless you outside production.

process

We don't make a million of anything. At worst case it just adds one more part to the hundreds that already have no second source.

In any case, it's better than it not fitting on the board. I still like SOT-523s and SC-70s. ;-)

How about this?

Jamie

If you looked at our parts inventory, fewer than 1% have a known second source... and I suspect that there's no more than 10% where there even *is* a second source. I bet your parts inventory is similar?

Granted, if we hired Joerg to come on in and tweak all the designs, I bet that perhaps upwards of 1/4 to 1/3 of all parts could be changed to something with a second source. :-)

(Granted, that makes the most sense only when you hit, say, at least 1,000+ or perhaps 10,000+ widgets/year, I suspect.)

---Joel

Other than resistors and caps, sure. We often have a second for those because I don't like being bothered when they reorder. ;-) A lot of other components are fairly easily replaceable (op-amps, gates, and jellybean stuff). Then there is a class, of perhaps a hundred parts, where a replacement would be somewhere between painful and disastrous.

Maybe. Don't know how you propose to do a second source on the radios. ;-)

So does Chinese production, but I don't want that job either.

Right, although there footprints don't match as often as I'd like!

True!

We roll our own radios, since for the modulation schemes/data formats/frequency ranges we want to use there isn't really anything appropriate off-the-shelf. No doubt this costs more than the nice ISM-band DSSS modules you guys have... but when you look at old systems like the Telex BTR-800 that's been around for decades, using regular old FM, and still fetches ~$1,500 for the beltpacks... well, clearly there's enough margin to support competiting systems with widely varying production costs and customers really are much more interested in features & performance than price. It's a nice market to be in! (...even if the only way Joerg is ever going to end up using one of these systems is if you or I donate one to his church... :-) )

I suppose the problem there is that, once you sign up to coordinate Chinese production, there's no stepping down -- it's not just a job you spend a few months doing and then can largely sit back and ignore, while it keeps running seamlessly for years on end...

---Joel

I try to avoid any opamp that isn't in industry standard pinout.

Oh yeah, should I tell our pastor already? :-)

Just kidding, we are pretty happy with what we've got. Thou shalt not envy ... Except we'll need more of those some day.

Actually, it can. Some of my designs are built in Shenzhen and other than the very occasional alternative source request it pretty much does run seamlessly for years on end.

Of course there is not one part in those designs that doesn't have at least four sources ;-)

We don't have a lot of problems with that, at least for standard op-amps. Some are high power or audio amps, so wouldn't expect a standard pinout. Of course there's SO, MSOP, and TSOP flavors of some but not others.

Dunno, someone is paying the engineering. Those radios aren't cheap.

I don't think he'd want one of ours. I don't imagine his pastor has a director, ten assistant directors, a lighting crew, sound crew, and a camera crew. ...or plays football. ;-)

Don't forget the moving to China part.

Yes, certainly a good idea. What I've been finding lately in that, while there's a small number of places making variable-gain amplifiers in SO-8 packages, none of the manufacturers seemed to have bothered to use the same footprint as the other ones... :-( -- I expect the same is true for many "non-generic" amplifiers -- e.g., instrumentation op-amps, fully differential amps, etc.

Mmm... perhaps not quite yet! ;-)

Hopefully you have lots of, e.g., WiFi access points and other 2.4GHz stuff running so that life is made that much harder for Keith's units. :-)

I did like your original idea of just pressing DECT phones into service as a poor-man's wireless intercom...

Nah, they work fine. If you're paranoid, simply buy the 900MHz model. ;-)

Our beltpacks use either rechargeable Li-Ion or "AA" alkalines. ;-)

I'd have to admit that 900MHz is actually a pretty good band right about now.

We've spent a lot of time discussing various battery approaches -- the one you have, where you can snap in your choice is a good idea, IMO... at least once you've decided not to go with the "sled" approach (which has its own pros and cons). If you really want to get fancy, perhaps you can license that Microsoft idea that mechanically makes it so that the orientation of the AA's doesn't even matter, i.e., it's impossible to put the cells in "backwards!"

Have you had many requests for really-small listen-only belt/bodypacks? I was talking to a guy who works for a production company last week, and he was saying he wished their wireless intercom suppliers would offer such an option.

---Joel

That's one reason I like PIN diodes. You can get some with at least

It has to be large-signal tolerant. Someone might plop their laptop right on the rack with antennas sticking out and forget to turn WLAN off. For a slide show or something. Some people don't even know how to turn that off, or even that it can be turned off. Luckily our stuff runs at UHF and the pastor's mike at VHF.

But I did have two phone systems here at 2.45GHz. One from Cincinnatti Microwave (that was the best, almost had a mil-spec feel to it) and another was AT&T branded. Both worked happily right next to a laptop with the WLAN going.

Yes, although alkalines require frequent opening and DECT phones have a tough to open battery compartment. So its doesn't pop open upon every tumble.

Hadn't seen that. I've seen shoulders around the '+' cap, but nothing that I thought was all that inventive.

Not that I know of. We do make a version that is listen mostly[*] (only uses one TDMA slot for however many listen-mostly belts you want to run). You're still buying the whole enchilada, though.