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[SOI Sentinel]

This is sorta in the vein of the Cypress PSoC's...

Anyone who's ever used a Cypress (as I have ) know they don't have much horsepower. Pairing one via SPI with an AVR or even a dsPIC gets around, but now you're doing programming in 2 separate controller cores for an (admittedly flexible) option. Now, how about just getting a Field Programmable Analog Array?

2 places are in active development, all the others stalled or had issues:

http://www.latticesemi.com/products/ispPAC/index.cfm

Lattice Semiconductor, which tailors it's ispPAC series to specific uses. They seem to do programmable everything. Their PAC series seems to have problems with frequencies over 750KHz.

http://www.anadigm.com/

Anadigm, who are more general purpose (and adding on an 8 Configurable Analog Block device series shortly to their 2 and 4 CAB array devices), and provide free software with some rather nice built-in functions already for making various analog parts. These are the guys who patented the switched capacitor network while they were at Motorola and bought the patents and buisness from Motorola when they parted ways. Their parts have accurate capacites to 2MHz, and if you can handle not being that accurate, they'll operate to 8MHz.

They'd make great strides for sensor conditioning (one chip, multiple sensors possibly, no external components), but they're eluding me as to finding an online supplier (in small quantities). Although it seems that the local distributor may be able to help me (must contact sometime this week).

And it'd be another unique offering for your customers

[sparky]

SOI - You are amazingly informed! I simply don't keep up as well as I should. Keep filling us in with the FPGA/PSoC info.

The FPAAs are interesting - I've never heard of them...

-Nathan

[Guest]

FPAA's are a rare breed. Ther have been three other companies that tried to create these. One went under (they also wanted $20 a chip!), one was reorganized and the FPAA "disappeared" from their product lineup, and the last one, Zetex, still exists, but have one product and it doesn't appear to be all that well supported.

http://www.zetex.com/3.0/a5-6.asp

Theirs appear to need an external controller of some type (microcontroller or support chip) to load the configuration at startup, and they need a split 5V supply. I'm still trying to compare all the different types at this time.

Only real issue I see is a possibility of cost. You're looking at a bit.

For instance:

Code: Select all

Lattice (Avnet prices)

		Price		Min Quanitity	Notes
ispPAC10	$10.285		39		Specialized A/D converter front end
ispPAC20	$8.80(9.955)	160(52)		Specialized A/D converter front end
ispPAC30	$10.285		39		Specialized A/D converter front end
ispPAC80	$10.285		40		5th order filter

Anadigm (Insight prices, single sample, appears to be the same for bulk)

		Price		Notes

AN120E04	$7.10		Standard 2x2 CAB
AN121E04	$8.20		Enhanced IO 2x2
AN220E04	$10.95		Dynamically Configurable 2x2
AN221E02	$4.95		Enhanced IO 2x1
AN221E04	$12.05		Enahanced IO Dynamically Configurable 2x2

Best I can tell, "enhance I/O" means that there's an onboard SAR 8 bit ADC that can use an analog out as a serial interface to a microcontroller, nothing more.

More expensive than individual parts, but they can be reconfigured. I haven't had time to dig into all the information available. From above, the Lattice ispPAC appear to be forcused on signal conditioning, the Anadigm FPAA's are more general purpose (and cheaper in small quantities). I'm looking into if you really need a special programmer for anything, or if a nice SPI connection from a PIC could do all the programming, even for the non dynamically configured FPAA's (which, BTW, just need a power cycle to reconfigure).

Individual components may provide higher performance, but you can't easily tune or have them self-tune in system. You're paying for flexibility. Probably great for test bench stuff, or digital RF tuning.

[SOI_Sentinel]

Crud, I thought I was logged in

[msutherl]

This is an old topic to bring up, but has anybody done anything with these since?

I've found this: http://servenger.com/products/index.htm
But very little information comes up in search engines.

I'm interested in using these for prototyping interfaces for very fussy sensors. Seems like it would save me a lot of time to have a programmable analog front-end to my microcontroller rather than messing with Wheatstone bridges, instrumentation amplifiers, and filters.