Where to buy HP Ic's? - Page 1
Forum section: electronics / general

author: Simon Spiers
author_rank: Regular Contributor
timestamp: May 01, 2019, 12:45:25 pm
content: I am desperate to find an HP DAC for a Hp1345a display unit and so far have had no luck cross referencing the part number.The IC is an 8 bit Dac part number ic 1826-1457.Anyone any the wiser?Thank you.

author: PA0PBZ
author_rank: Super Contributor
timestamp: May 01, 2019, 01:57:01 pm
content: https://www.aerospaceorbit.com/nsn/nsn-parts/5962012028625/

author: splin
author_rank: Frequent Contributor
timestamp: May 01, 2019, 02:13:46 pm
content: OK, looks like someone has come up with the answer whilst I was typing this but I may as well post it anyway for future reference or the unlikely possibility it isn't an AD556...Assuming that it's not a specialized or custom high speed video DAC, then chances are it's a re-labelled commodity DAC that was around when the equipment was designed. If you have the schematic then try to find a matching part according to operating voltage, modes (voltage or current output, bipolar, multiplying etc.), serial/parallel, internal/external reference, pin labels and pinouts with 8 bit DACs from the era such as AD558 or DAC08.If you can provide any more information including package type and any pinout info including voltage rails you can identify, then someone may be able to list some likely candidates. A photo may be very useful.Failing that you could try reverse engineering the circuit and substitute something suitable on a small daughter board or even use a microcontroller with a DAC if the interface or timings are particularly peculiar.

author: Simon Spiers
author_rank: Regular Contributor
timestamp: May 01, 2019, 04:57:55 pm
content: Thanks for the replies. I have tried this company and they wanted $150I have attached a extract of the circuit so show pinouts ect.

author: RobertPS
author_rank: Contributor
timestamp: May 01, 2019, 05:42:15 pm
content: This one might be an equivalent, but check the data sheet for the pin out:https://www.ebay.co.uk/itm/ci-DAC-1266-LCJ-ic-DAC1266LCJ-AD566AJD-BIN-DIP-24-ceramique-PLA024/201503267586

author: Simon Spiers
author_rank: Regular Contributor
timestamp: May 01, 2019, 06:58:58 pm
content: Sorry looks like it is actually a 12bit dac!

author: Gyro
author_rank: Super Contributor
timestamp: May 01, 2019, 07:14:08 pm
content: You could maybe try Sphere, they are pretty much the ultimate source. Not local though...https://www.sphere.bc.ca/test/hpparts.html

author: Simon Spiers
author_rank: Regular Contributor
timestamp: May 01, 2019, 08:01:14 pm
content: Looks like the AD566AKD is a good match?

author: splin
author_rank: Frequent Contributor
timestamp: May 02, 2019, 02:29:31 am
content: Quote from: RobertPS on May 01, 2019, 05:42:15 pmLooks like RobertPS nailed it - pinout is the same and all the specs I scanned seemed to match. I'd say the DAC1266 was a direct equivalent of the AD566 - or vice-versa.

author: Simon Spiers
author_rank: Regular Contributor
timestamp: May 02, 2019, 12:47:12 pm
content: Thank you all for helping me. I really appreciate this. I have ordered a AD566AKD and hopefully put the unit back on the road to recovery.

author: OH2LIY
author_rank: Contributor
timestamp: May 03, 2019, 07:21:37 pm
content: Hi, I finally did remembered to dig my storage. I have whole PCB where those DACs are located. I did got HP8753A and there was straight line on CRT (don't remember X or Y). Last OP before output driver transistor was bad, and I didn't manage to find replacement. I'd have to buy whole PCB to fix display. Everything else works, because I remember to use scope on XY mode and got nice picture.

author: Simon Spiers
author_rank: Regular Contributor
timestamp: May 03, 2019, 08:12:50 pm
content: Are you offering the board for sale?

author: OH2LIY
author_rank: Contributor
timestamp: May 05, 2019, 12:36:50 pm
content: I don't have anymore HP8753A and there is no need for spare parts. Make offer if you are interested (mailing fees could be incredibly high, but card could fit inside large bubble envelope with extra protection)?Ramppa

author: Simon Spiers
author_rank: Regular Contributor
timestamp: May 05, 2019, 03:58:14 pm
content: Well thanks to the excellent support here i'm up and running again.I bought a AD566AKD and no problems at all.Thank you all so much.And remember that an HP 1826-1457 is a AD566AKD !