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What's so special about these op amps?

I found these devices at the "swap shop" at our dump; not having any idea of what they were. I Googled them and found this:

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Summary: ? Bandwidth 12MHz ? Input Impedance 500M? ? Input Bias Current 1nA ? Input Offset Current 1nA ? Input Offset Voltage 0.5mV ? Gain 150kV/V ? Slew Rate 7V/µs

The data sheet has a 2006 date & there weren't many sites offering them,

but a couple that did had prices up to $43! Each! WTF? What makes these so dear? (It's probably obvious, but not to me, if so please excuse my newbie-ness.)

Bob

Reply to
Bob Engelhardt
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2902, isn't that a variation on the LM358 (158/258/...)?

Price doesn't mean much, could be scalpers trying to scam people on availability.

Tim

-- Deep Friar: a very philosophical monk. Website:

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Summary: ? Bandwidth 12MHz ? Input Impedance 500M? ? Input Bias Current 1nA ? Input Offset Current 1nA ? Input Offset Voltage 0.5mV ? Gain 150kV/V ? Slew Rate 7V/µs

The data sheet has a 2006 date & there weren't many sites offering them, but a couple that did had prices up to $43! Each! WTF? What makes these so dear? (It's probably obvious, but not to me, if so please excuse my newbie-ness.)

Bob

Reply to
Tim Williams

Dear? Because they're no longer made and probably because some audiophool thinks "they're pretty".

The only unusual thing is the input bias scheme _cancels_ out (pretty much) the input current, thus the claimed "hi-Z". ...Jim Thompson

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| James E.Thompson, CTO                            |    mens     | 
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Reply to
Jim Thompson

There MIL-SPEC parts so the price is jacked through the roof. Now you know why the government is broke.

Reply to
bloggs.fredbloggs.fred

Most likely because in this day and age a TO-can for an opamp makes it a boutique part, just like a ceramic DIP package would. Maybe there were also some incantations, those can be expensive :-)

--
Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

Vsupply max = 45V. A feature of old technology rather then intended high voltageness.

VLV

Reply to
Vladimir Vassilevsky

You don't need such a dinosaur for that. I used a 44V opamp from fresh production in a design lately, just a regular COTS part from ONSemi I think. If someone needs to know I can dig it out.

But that one doesn't come in a glass tube or TO can :-)

--
Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

Try to find one to buy. Maybe that will tell you something.

Reply to
John S

?

If you're building a replacement board for something military then you have to use the exact parts called out -- changing a part means you're redesigning the board, redesigning the board means you need to test it up the wazoo.

$43/ea can be a lot cheaper than the effort to verify that your chosen replacement part really does work in the circuit over temperature and whatnot, then to redesign the board to take a (probably) DIP package, then to formally verify that everything works, then to do all of the paperwork to upgrade the revision of the system that the board goes into, etc.

--
Tim Wescott 
Control system and signal processing consulting 
www.wescottdesign.com
Reply to
Tim Wescott

So, there's nothing special about what they do - it's just the mil spec-ness and the rarity that costs so.

Thanks, Bob

Reply to
Bob Engelhardt

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