I was trying to order a small stock of OPA2604 for one of our engineering groups, only to find out that no major distributor on both sides of the pond has it in stock; there is also no option to order it directly from TI (this was a cost no objection purchase). Finally, I got Element14 (aka Newark) to procure these little critters directly from TI, through insider channels. Note that TI does not mention anywhere about this part being EOLed or otherwise cancelled. The OPA604 single opamp is available everywhere without any constraints.
But the second day I got a call, then an email with a "Non-conforming" form (attached) that I am supposed to sign to have the order through. This document clearly states that the OPA2604 is no longer supporting +/-24V supply and has to be constrained to +/-20V. No word about such a change in the TI datasheet.
So this high voltage part is almost toast. I suppose TI has a rather large non-conforming stock, but they are not releasing it to distributors and delivers only against signing the attached form.
The short technical description of the symptoms at +/-24V supplies long term large offset drift and increased Iq makes me strongly believe that the issue is thermal in nature (this chip runs rather hot). Anyway, it is unlikely TI is going to re-design the chip or the packaging process (to accommodate more thermal relief), since this is not a hugely popular chip in the industry, and the audio applications are known as not being large revenue providers (to put it mildly).
Anyway, for the time being, this nice chip (the only dual jfet high voltage on the market, as far as I know) will remain unobtanium. If you have some in your stash, restrict the supply to +/-20V (some may survive +/-24V a la longue, but I would not count on this). Or use the 2x OPA604 single opamps instead, that device doesn't have the problem (that's likely what our group is going to do, I suppose).
But the second day I got a call, then an email with a "Non-conforming" form (attached) that I am supposed to sign to have the order through. This document clearly states that the OPA2604 is no longer supporting +/-24V supply and has to be constrained to +/-20V. No word about such a change in the TI datasheet.
So this high voltage part is almost toast. I suppose TI has a rather large non-conforming stock, but they are not releasing it to distributors and delivers only against signing the attached form.
The short technical description of the symptoms at +/-24V supplies long term large offset drift and increased Iq makes me strongly believe that the issue is thermal in nature (this chip runs rather hot). Anyway, it is unlikely TI is going to re-design the chip or the packaging process (to accommodate more thermal relief), since this is not a hugely popular chip in the industry, and the audio applications are known as not being large revenue providers (to put it mildly).
Anyway, for the time being, this nice chip (the only dual jfet high voltage on the market, as far as I know) will remain unobtanium. If you have some in your stash, restrict the supply to +/-20V (some may survive +/-24V a la longue, but I would not count on this). Or use the 2x OPA604 single opamps instead, that device doesn't have the problem (that's likely what our group is going to do, I suppose).
Are you sure? I clicked on your link and got the attached. Do you see it different from your side of the pond?
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Unfortunately I was looking for ~100pcs. And if there's no way to get the part in quantities, then there's no point designing with it.
At 350nA input bias OP275 is not a jfet input opamp (compare to 0.1nA in OPA2604). The absolute maximum rating is +/-22V compared to +/-25V in the original OPA2604 spec. I would not use an OP275 beyond +/-20V which is coincidentally what the new OPA2604 spec recommends.
Unofficial sources from Asia are not an option, those are 90% fakes, I wouldn't touch them with a 10 foot pole.
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