Harris IC ID

I have a PCB with a part marked:

H721A F749AMD

It's an 8 pin SOIC, with power (+5 VDC) at pin 8 and GND at pin 4. Could be an op-amp or TTL based on expected function.

I'm assuming Harris - the "H" is a bit bolder than the rest.

Only a few years old, not ancient.

Google seems to have no clue except that the H721A has been asked about on a sci* group in the past, apparently without a solution.

It really shouldn't be anything unusual or custom,

Some of it's pins are connected to the outside world via 100 ohm series resistors. Part of an interlock on a laser.

Any info appreciated.

Thanks!

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On 30 Jan 2009 11:42:30 -0500, snipped-for-privacy@repairfaq.org (Samuel M. Goldwasser) put finger to keyboard and composed:

FWIW, I found this tiny snippet of info on a part that may be related to the H721A:

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H723A IC,ESD/OVERVOLT PROTECT,S

H723A SOP-8P INTERSIL

Another clue may be this post:

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The author writes:

"I'm trying to find the manufacturer of a IC in the PicStart board, it's a SO8 dual SPST switch and it's marked H721A.

I've found the analog device ADG721, but I'd like to know others manufacturers."

Microchip's PicStart manual states that the "PICSTART Plus development programmer features ... special circuit design techniques to enhance ESD protection."

Here is the datasheet for the ADG721/722/723:

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It states that "the ADG721/ADG722/ADG723 features proprietary ESD protection circuitry". The part is described as a "CMOS Low Voltage 4V Dual SPST Switch".

I suspect that the H721A is in fact compatible with the ADG721.

- Franc Zabkar