Packages containing matched FETs?

[merlinb]

Anyone got any bright ideas for finding matched JFETs or MOSFETs as an alternative to the old 2N5452 dual-FET package?

I seem to remember one of the CD4000 series containing a couple of discrete MOSFETs, but I can't remember which. Any other cheap ICs contain 'free' FETs?

(No, matching individual FETs by hand will not do for my purposes)

[slacker]

CD4007 has discrete N and P mosfets, I don't know how matched they are. Can't help with dual jfets, I've never used any.

[R.G.]

Advanced Linear Devices makes matched pairs, quads, and complementary quad MOSFET packages. Mouser stocks them, which may not help you much.

The dual JFETs are going, or have gone, the way of the dodo, even the surface mount packages. The only real hope is back stock.

[evogel99]

http://www.linearsystems.com/products.html#GlossD

[DavenPaget]

Advanced Linear Devices makes matched pairs, quads, and complementary quad MOSFET packages. Mouser stocks them, which may not help you much.

The dual JFETs are going, or have gone, the way of the dodo, even the surface mount packages. The only real hope is back stock.

I can't find any dual jfets . but yeah , gone the way of SMP .
none of the mosfets array are in DIP .

[a soBer Newt]

I was talking with the guys from Linear Systems at NAMM, they seem very devoted to making jfets in the process of finishing a P-Channel currently. More likely then not they will be SMT.  I have been working with the LSK390 quite a bit recently its a rather nice chip not a difficult SMT to solder.

[davent]

Linear Systems advertise a LSK389 dual Jfet (2sk389) in recent editions of AudioXpress.

[PRR]

Old analog switches multiplexers were multiple FETs on one die.

Many of these have been obsoleted for CMOS or for more integrated system-chips (MUX+ADC+etc).

AH5010, AH5011, AH5012, AH5020C
http://www.ti.com/lit/ds/snosbh8a/snosbh8a.pdf

I bet these are long out of production. (The "AH" means "Hybrid" so they are not truly integrated/matched and are/were labour-intensive.)

Future Electonics claims to have stock of a quad MOS in DIP.
http://www.futureelectronics.com/en/Technologies/Product.aspx?ProductID=SD5000NCALOGIC8266611

[R.G.]

As a side note, I thrashed through this issue when I did my JFET and MOSFET doublers. It's quite difficult to get good ones.

[PRR]

> one of the CD4000 series

4007

[Ronan]

Sometimes http://octopart.com/ is useful. Usually you will have to do a RFQ. Worth a try, but shipping can be expensive, and the supplier might not want to sell small quantities. All one can do is put in the RFQ and see what comes back.

[merlinb]

Thanks for the responses everyone! I will have a look at the CD4007. Not yet sure how having the substrates all connected together will affect my topology, but you never know.

[R.G.]

You'll be wanting this:
http://electronicdesign.com/article/analog-and-mixed-signal/what-s-all-this-cd4007-stuff-anyhow-6073.aspx
from one of my personal heros.

I used the 4007 in one version of the MOSFET Doubler, and it worked well. The substrate issues you mention largely resolve down to putting the V+ and V- pins at voltages which keep the substrate isolation diodes from conducting on any signal or power supply level. When you get that, you can ignore the substrates for most purposes.

A bigger issue is that the 4007 has three pairs connected up in different manners on the chip so you have to work around the connections that are already in there. That can be tricky. But it's manageable.

[DavenPaget]

http://sg.element14.com/jsp/search/productdetail.jsp?sku=2061516 

[PRR]

Complementary pair. P and N.

Merlin seems to want a same-type pair.

[wavley]

Old analog switches multiplexers were multiple FETs on one die.

Many of these have been obsoleted for CMOS or for more integrated system-chips (MUX+ADC+etc).

AH5010, AH5011, AH5012, AH5020C
http://www.ti.com/lit/ds/snosbh8a/snosbh8a.pdf

I bet these are long out of production. (The "AH" means "Hybrid" so they are not truly integrated/matched and are/were labour-intensive.)

Future Electonics claims to have stock of a quad MOS in DIP.
http://www.futureelectronics.com/en/Technologies/Product.aspx?ProductID=SD5000NCALOGIC8266611

I've had a MUX-28 on my bench for five years dying a slow death as a surface to sharpen my tweezers and pin tips, the poor thing is just about worn smooth, maybe I'll give it a second life as some sort of fuzz.

[PRR]

> I've had a MUX-28 on my bench for five years

Not old enuff for "multi-FET". It has decoders. You can't fondle the naked Gates.

Would be a lovely low-THD audio switch.

[DDD]

2N5911(12)
LS3954(
U421(23)
U440(41)
NTE461

[merlinb]

New question:

Can anyone tell me which opamps (or opamp-like devices) provide their own Vref internally?

In other words, devices that only need an input coupling cap for DC isolation- no Vref divider required. I know there's one that is mentioned quite often on this forum, but I can't remember the number (some kind of small power amp IC perhaps?)

[frequencycentral]

New question:

Can anyone tell me which opamps (or opamp-like devices) provide their own Vref internally?

In other words, devices that only need an input coupling cap for DC isolation- no Vref divider required. I know there's one that is mentioned quite often on this forum, but I can't remember the number (some kind of small power amp IC perhaps?)

Are you thinking of LM386, which some use as a vref?