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I'm struggling to identify the origin of the IC in the attached image. I believe it is a rebadged HP/Agilent part:1826-1488, ADC CMOS 12-BIT 20-PIN. can you tell from the logo who makes it then I can try to track the original part number and perhaps find a replacement part if no longer in production.

it's in a HP system power supply (HP 6624A).

enter image description here

P0B
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  • That looks like an old National Semiconductor logo. – brhans Jun 11 '18 at 20:09
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    It's a National Semi logo, with an Agilent/HP internal part number. That means National made a "custom" version (maybe just modified test parameters, or maybe just custom marking, maybe a completely custom design) for HP/Agilent. – The Photon Jun 11 '18 at 20:10
  • @brhans I would think it's Analog Devices (AD). Unless it is explicitly telling us it is an ADC... – Eugene Sh. Jun 11 '18 at 20:10
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    TI bought NSC look there – Tony Stewart EE75 Jun 11 '18 at 20:11
  • @EugeneSh. [old natsemi logo](https://www.google.com/search?q=national+semiconductor+logo&tbm=isch&source=iu&ictx=1&fir=rETldVdz4Uj-CM%253A%252CpKy9dsym-8gvtM%252C_&usg=__vqSRfPfUuB5HTYmzjAvXMYFe-0o%3D&sa=X&ved=0ahUKEwi6xqDKtczbAhWro1kKHWcxBuQQ9QEIMTAD#imgrc=rETldVdz4Uj-CM:) – brhans Jun 11 '18 at 20:11
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    @EugeneSh., I dunno what the "AD" stands for, but compare it to this part: http://www.cpu-world.com/CPUs/32016/National%20Semiconductor-NS32016N-10%20(NS16032N-10).html – The Photon Jun 11 '18 at 20:12
  • @ThePhoton Pretty convincing :) – Eugene Sh. Jun 11 '18 at 20:13
  • @P0B Related: https://electronics.stackexchange.com/questions/334128/how-do-i-identify-smd-components-or-how-do-i-identify-any-component/334129#334129 – Voltage Spike Jun 11 '18 at 20:31
  • The current [service manual](https://literature.cdn.keysight.com/litweb/pdf/06626-90003.pdf?id=1000002468-1:epsg:man) for the 6624A gives cross references for many of the parts, but I don't see 1826-1488 listed there. The only ADC that's called out is an AD7534. That is a 14-bit rather than 12-bit part, but it is available in the same 20-pin DIP as your part. Maybe they're now using the AD part because the old NS part is obsolete --- you could check to see if the pin-out of the AD7534 makes sense in your circuit. – The Photon Jun 11 '18 at 20:36
  • Might be a custom part, I can't find a trace of it – Voltage Spike Jun 11 '18 at 20:39
  • Just realized, the AD7534 is used at the exact same designator (U321) in the newer 6625A where your mystery part is used in the 6624A. Again, I'd check if the AD7534 pin-out makes sense in the older design. – The Photon Jun 11 '18 at 20:49
  • @the photon , the part is listed in the service manual: http://ridl.cfd.rit.edu/products/manuals/Agilent/power%20supplies/CD1/Service/6621Aser.pdf page 5-21 , U313 – P0B Jun 11 '18 at 20:53
  • @PDB, but there's no cross-reference to the manufacturer PN. In the Service Manual for the newer design (linked above), they cross-reference to the AD part I mentioned. But obviously that is a different design, since it's a 14-bit ADC instead of 12-bit. So you're going to have to do some work yourself to see if the new part can be used in the old board. – The Photon Jun 11 '18 at 21:00
  • Now that @crj has located a cross-reference, it doesn't look like it would be easy to use the AD part as a replacement for the NS one. – The Photon Jun 11 '18 at 21:15

1 Answers1

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You are correct about the HP part number. The cross reference from this HP cross reference guide is shown below. Note that it is marked as "SELECTED". This means that it was a selected for specific characteristics, as described in the second snippet from the document shown below.

The part is apparently out of production, but there are a few of the National Semiconductor version currently on eBay. They have a 1989 date code, but are listed as unused.

Here is a link to the datasheet for the National Semiconductor part.

enter image description here

enter image description here

crj11
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