Locating an Agilent ASIC (3GHz Frequency Divider) // Repairing a 8133A Pulse Gen - Page 1
Forum section: electronics / repair

author: danielbriggs
author_rank: Regular Contributor
timestamp: August 14, 2024, 02:23:59 pm
content: Hey all,I just thought I'd check in here to see if anyone more well versed in locating hens teeth Agilent ASIC's could help me find 1x part.I'm slowly repairing an 8133A Pulse Generator (Opt 3 with the 2x channels).Pretty much got everything working in spec apart from 1x thing. The pulse widths the generator makes goes a bit wobbly between very specific frequency bands, and is rock solid at all others.The behaviour is seen on both channels (each board "A7"). Due to the way the instrument is made both output channels derive their timing from board "A5" I've tracked it down to that.Jitter between:31-38MHz61-75MHz123-149MHz248-298MHz493-596MHz984-1000MHzThe YIG is programmable between 2-4GHz, and the divider is bypassed above 2GHz. The unit performs excellently >1GHZ, it's only these lower frequency bands, making me think the divider is failing.The instrument is full of lots of rocking horse *** type IC's and lovely ceramic hybrids.I've attached an image of the strange circular IC I think is failing.Markings:0-68660030E47I've never seen a package quite like it (but then again I rarely stray into RF wizardry!)The spec I think it has is described as:ASIC Divider spec:Input frequency range: DC-3GHzDividing range: 1,2,4,8,16,32,64Output levels: ECL, differentialInput sensitivity: 200mW pp single ended or 100mW pp differentialSo, does anyone know what specific this part number is + where I can get one?Or would it be exclusively made for Agilent with no chance of buying a replacement?If the latter I'll wait for a cheap A5 board to come up on eBay; test, replace / transplant.Any pointers or help would be really appreciated.Thanks again,Dan

author: Xtremexp
author_rank: Regular Contributor
timestamp: December 13, 2024, 04:19:41 am
content: Hello,were you able to identify the issue or find the replacement chip?I am also facing similar issue but in different frequency band. My unit jitters in 400MHz to 700MHz band.

author: danielbriggs
author_rank: Regular Contributor
timestamp: December 13, 2024, 10:41:51 am
content: Unfortunately not yet. It's still on my list of things to repair.I did get a spare similar board with some donor IC's on I need to transplant at some pointI'll let you know if I ever get it fixed up such it might help you in the future.

author: Xtremexp
author_rank: Regular Contributor
timestamp: January 18, 2025, 09:36:18 pm
content: Did you getQuote from: danielbriggs on December 13, 2024, 10:41:51 amDid you get chance to fix it? I am also looking for donor IC.. but I am not able to find one..

author: danielbriggs
author_rank: Regular Contributor
timestamp: January 18, 2025, 09:45:36 pm
content: I did get a donor board and replaced this IC, but unfortunately the fault still remained.So it’s back to the drawing board on what next to replace to get the PC board working.The good news is now I have a board to borrow IC’s from.Also, I would have a spare working IC in theory should you need one and that fix yours.Will keep you posted on the repair should the info from my unit end up being helpful to you.I will get to the bottom of it as time allows around work/life.All the best,Dan

author: Xtremexp
author_rank: Regular Contributor
timestamp: September 26, 2025, 09:04:17 pm
content: Hey Dan,I am still stuck in this issue. Have you get chance to look into yours?.I cannot source the divider IC to replace mine