Multiple MOSFETs in a single package?

[MacAttak]

I was looking at this application note about bi-directional level shifting: http://ics.nxp.com/support/documents/interface/pdf/an97055.pdf

The design calls for discrete MOSFETs (N enh) plus some passive resistors. For a simple shifting implementation, it requires two transistors per signal line. In this case, I would like to perform automatic level shifting for a lot of signals - roughly 80 to 90. Going with discrete transistor packages, there is no way I could hope to fit that many (plus three resistors for each signal) on a PCB of reasonable size. And while buying a few chips won't break the bank, when you need ~200 for a single board it adds up. Example transistor mentioned in the app note: http://www.digikey.com/product-detail/en/BSN20,215/568-1658-1-ND/763485

I've tried looking for multi-FET array packages for this application, but haven't turned up anything. Surely someone must offer quad FETs in a single chip (or 16, or even 8 )?


I know that normally, you would only perform level-shifting on the few signals you care about, but in this case I want to have a general-purpose level shifting adapter that lets me plug average 5v Arduino-style shields into my FPGA board that only wants 3v3 (and I don't think it is 5v tolerant, nor would I expect the 5v shields to be 3v3 tolerant).


All of the purpose-made level-shifting chips I have seen that can handle multiple signals are useless for this purpose, because they are either unidirectional or they require another external signal to control the direction of all shifted lines.

[duskglow]

I have some dual mosfets in a SOP-8 package.  Pretty compact.  CEM4953 (I believe).  I bought 50 for around $16.

[c4757p]

Two MOSFETs per SOIC-8 is huge if you want to level shift 90 signals with them!

[duskglow]

It was SOP-8.  My mistake.  They're pretty little guys.

[croberts]

DigiKey does have MOSFET arrays in Product Index --> Discrete --> FETs - Arrays but only 4 per package max as matched pairs.

[free_electron]

there are chips that have that circuit avaialble in ulti lanes ( up to 8 i believe ) maxim and linear technologies have em. max 37xx series i believe.  made for i2c and spi buses

st has one in flipchip ( really tiny )

[Rufus]

Analog do some octal bus switch/passive level translators. ADG3300 is a 5v capable example.