Stabistor diode STB523 - anybody got a datasheet? - Page 1
Forum section: electronics / general

author: david77
author_rank: Frequent Contributor
timestamp: June 24, 2012, 09:32:18 pm
content: I've been looking online all day to find some info on a stabistor diode STB523. Had no luck so far.Has anybody got any info on this part? It's used in a HP power supply.HP part no. 1901-0460

author: free_electron
author_rank: Super Contributor
timestamp: June 24, 2012, 11:22:33 pm
content: If memory serves me well that's a diode stack: a bunch of diodes in forward mode ( not a zener ! ) 15 volts made by General Electric. looooong gone ...the difference with a zener is that it does not conduct in reverse.a zener in reverse acts like a diode : 0.7 volts drop . stabistors don't do this. i homebrew these using a simple 1n4007 and a 14.3 volts zener. works fineCode:Z14.3v 1n4001---|<|---------|>|---\Fixing a 6236A ?

author: david77
author_rank: Frequent Contributor
timestamp: June 25, 2012, 06:36:37 am
content: Quote from: free_electron on June 24, 2012, 11:22:33 pmNot exactly. I am thinking about building one from scratch.So you just put the 14,3V Zener and the 1N4007 in series, anode to anode? Which side represents the anode and kathode of the original STB then?No, hang on I think I can answer that myself: Kathode is kathode side of 1N4007, anode is anode of 1N4007, too. Right?The dash in the second line is not important, I take it?Thanks for your help, much appreciated.

author: Shuggsy
author_rank: Regular Contributor
timestamp: November 22, 2012, 05:38:35 am
content: Sorry to dig this up from the grave, but I think this just became relevant to me as I am indeed fixing an HP 6236B!I'm hoping you can help me understand the STB523 diode a little more free_electron (or anyone else feeling the need to comment...). If I have things straight, it's merely a stack of diodes that has a threshold of 15V before it begins conducting when forward biased? This opposed to the 0.7V like a 1n4007 or similar?I pulled one of these out of my supply because the current limiting behavior started at a lower output current that it should have on my supply and one of this is in the circuit. Testing it on my bench, it started conducting around 1.8V when forward biased... so if it's supposed to have a threshold/forward voltage around 15V then this one is definitely headed to the trash bin and I'll be taking free_electron's advice on how to home brew one!Any help is appreciated!

author: poorchava
author_rank: Super Contributor
timestamp: November 22, 2012, 07:10:45 am
content: I think this is simply 21 diodes in series. For a current to pass through these, the voltage has to exceed the sum of forward voltage drops. Stabistors are supposed to be better for low voltage references. One example of such device is BAS17 (google for datasheet). I think that hacking up 21 1n4148's in series won't necessarily do the trick, because stabistor is optimized to have the voltage drop varying very slightly when current changes.EDIT:googled that one up:http://www.circuitsonline.net/forum/view/76899

author: Jebnor
author_rank: Regular Contributor
timestamp: September 24, 2014, 08:12:45 pm
content: Quote from: david77 on June 25, 2012, 06:36:37 amI'm thinking about doing the same thing. Well the 6236B. Did you complete your project by chance?

author: calexanian
author_rank: Super Contributor
timestamp: September 24, 2014, 10:27:18 pm
content: Voltage reference devices took over for those many moon ago. Chris Gammel was making a joke about them earlier. Stabistor. The most violent component or something like that.

author: scanny
author_rank: Newbie
timestamp: July 06, 2015, 02:31:54 am
content: For anyone encountering this thread on search, the expected forward voltage drop of the HP part 1901-0460 is indeed around 1.9V. So the one @Shuggsy had was good.There are a few of them in my HP 6281A which I just happened to be searching on, so thought I'd mention for anyone else who finds this thread.

author: schopi68
author_rank: Regular Contributor
timestamp: July 19, 2015, 04:20:24 pm
content: The Service Manual for the HP POWER SUPPLY PP-7548 lists the STB523 HP-Part no. 1901-0460 as a 1N4830 (which has 3 PN-junctions).

author: Ecogeek
author_rank: Contributor
timestamp: August 19, 2021, 08:53:32 pm
content: Service Manual HP power supply HP6256_HP6263_HP6264_HP6265_HP6266_HP6267_HP6271B_HP6274B_dc_power_supply. I found my two STB523 (CR8, CR36, diode, Si 3-junction, HP 1901-0460) Stabistors measured 2.1V in the working power supply. The exact voltage does depend on the current flowing and temperature, so the real-world circuit measurement is useful. Thanks for the reference to 1N4156 part being the equivalent which does have a downloadable datasheet. Even this reference on Wikipedia; at least something on the subject.https://en.wikipedia.org/wiki/Stabistorhttps://www.digitroncorp.com/getmedia/824DFFAE-F11A-451C-A8DF-65A92EFB02A5/1N4156-2c-1N4157-2c-1N4453-2c-1N4829-2c-1N4830-2c-1N5179-2c-MPD100-MPD400A.aspx?ext=.pdfHopefully, this is information is helpful to others working on vintage lab equipment.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: August 20, 2021, 10:55:54 pm
content: Maybe the part might be here?https://www.eevblog.com/forum/buysellwanted/fs-new-test-equipment-repair-parts-hp-agilent-tektronix-fluke-etc/msg1238752/#msg1238752

author: floobydust
author_rank: Super Contributor
timestamp: August 21, 2021, 12:57:00 am
content: 1901-0460 replaced by 1901-0468 Microsemi Corp for HP P/N: DZ890505C but I got no farther.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: August 21, 2021, 02:15:13 pm
content: How about this reference?Same as ecogeek1901-0460 01973 STB523-A01973 is GE Co. Semiconductor Prod. Dept.I think you already know this but the information is from this group, which I have found to be quite helpful:HP parts list onGroups.ioHP-Agilent-Keysight-equipment, maybe they could help further

author: 5065AGuru
author_rank: Frequent Contributor
timestamp: August 23, 2021, 03:25:18 am
content: The HP 5065A also uses a 1901-0460 in the lamp exciter.I have a replacement stock of the 1N4830 that is equivalent.Cheers,Corby

author: AMR Labs
author_rank: Frequent Contributor
timestamp: March 30, 2025, 02:15:13 pm
content: The 1901-0460 spec in the parts list of the HP6209B/07B manual says: "Diode Si 2.4V @ 100mA", and lists the 1N4830 as an alternate.Spec sheets of the 1N4830 I've found say its a 2.69V 0.1A silicon diode. Same current, slightly higher voltage.They are both 3-layer diodes, or 3 diodes in series in a single package, used as a voltage reference with very low temperature coefficient, "wherein each PN junction contributes aprox -2mV/degC".The CR7 reference diode in my HP6209B only measures about 2V drop, so wonder if its gone low over time (power supply from around late 60s, early 70s) and needs replacing to solve an issue with the meter circuit balance that uses a -3V reference voltage coming from a bias circuit associated with that diode. Reference voltage now measures low at only -2.3V.Anybody have a spare they want to sell? Ebay "vintage parts" prices are ridiculous.

author: coppercone2
author_rank: Super Contributor
timestamp: March 30, 2025, 09:24:44 pm
content: hP current sources use them too. I did wonder how well 3 melf diodes would perform if you link them

author: AMR Labs
author_rank: Frequent Contributor
timestamp: March 30, 2025, 11:47:53 pm
content: Voltage-wise probably, but temperature stability won't be as good, aside from the individual diodes not being matched as exactly.