| Products > Test Equipment |
| HP LCR/LCZ Comparator Handler Interface Recreation: 16064A |
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| squadchannel:
--- Quote from: ch_scr on August 01, 2024, 07:32:48 am ---Now, that helps with the two "mystery IC" U10 / U11. While still nothing is found for their part number 1990-0557 / 1990-0602, the schematics include enough clues to find a fitting replacement. --- End quote --- U11 1990-0602 was informed by keysight's parts finder. It is still available today. ($10) IF=20mA VF=1.75V BVR=5V Search is on for U10 1990-0557. MOD: 1990-0602 is also called 5082-4361 (4284A SM) and 5082-4361 is equivalent to HCPL-2601 (from the data sheet). |
| TERRA Operative:
--- Quote from: ZGoode on August 01, 2024, 02:09:52 am ---....but if you want the raw scan I can upload that to oneDrive. It's too big to upload here --- End quote --- Yes please! :D U10 looks like a dual optocoupler, could possibly be replicated with two discreet modern optocouplers? [EDIT] I'm gonna say this one is a dual channel open-collector optocoupler. The Broadcom/Avago HCPL-2630-000E and HCPL-2631-000E (latter has better common mode transient immunity) are pin compatible, see page 5 of the datasheet. I think the Vishay VO2630, VO2631, and VO4661 are all worth checking out too, and they are cheaper than the Broadcom part. (The three parts have different common mode transient immunity and propogation delays, I don't think these specs are overly important in our application) U11 is something funky, is that a NAND gate with an optocoupler on one input? Maybe something like an NTE3087? I wonder if there are modern equivalents?.... [EDIT] How about a 6n137? It looks pin compatible from a quick glance at the schematics... Seems the 6N137, VO2601, and VO2611 are all pin compatible here too. |
| squadchannel:
U11 is HCPL-2601 as I mentioned. 1990-0602 is listed as 5082-4361 on the 4284A SM. The commercial part name is HCPL-2601. The HCPL-2601 appears to be an optocoupler with a built-in AND gate. U10 is listed as an LED matrix display according to keysight Find-A-Part. Absolutely not. |
| TERRA Operative:
--- Quote from: squadchannel on August 01, 2024, 12:42:36 pm ---U11 is HCPL-2601 as I mentioned. --- End quote --- You did too, I completely missed that... :-DD Looks like they are under US$3 in quantity 1 from Mouser (Digikey has them on backorder). Well in that case, if U11 is a HCPL-2601 (the single channel type), I'd bet that U10 would probably be a HCPL-2631 (under US$5 each from Mouser) as it is the dual channel version of U11 with equivalent ratings. |
| squadchannel:
--- Quote from: TERRA Operative on August 01, 2024, 01:10:14 pm ---Well in that case, if U11 is a HCPL-2601 (the single channel type), I'd bet that U10 would probably be a HCPL-2631 (under US$5 each from Mouser) as it is the dual channel version of U11 with equivalent ratings. --- End quote --- The internal circuit of the HCPL-2631 consists of transistors, so it should work fine. One concern is that if the limiting resistor on the emitting side is 180ohm as shown in the original schematic, little bit more current will flow. According to the HCPL-2631 datasheet, VF=1.4V when IF=10mA. 360ohm is optimal for 5V operation. 20mA will flow with 180ohm. The absolute maximum rating is 30mA, so i don't think there is a problem. |
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