Need INA138  DIL 8 pin out - Page 1
Forum section: electronics / projects

author: outremer
author_rank: Contributor
timestamp: December 28, 2016, 09:27:22 pm
content: Hi all;I'm desperatly searching for the pin out of the current sensing amp INA138 from Burr Brown (now owned by Texas Instruments). The 5 pin SOP model is everywhere but the 8 pin DIP package has disappeared from earth's surface.Does anyone has info ?Best regards and season's greetings.

author: TimFox
author_rank: Super Contributor
timestamp: December 28, 2016, 10:51:43 pm
content: This link is to the original Burr-Brown data sheet (pre-TI):http://pdf1.alldatasheet.com/datasheet-pdf/view/56689/BURR-BROWN/INA138.html

author: outremer
author_rank: Contributor
timestamp: December 30, 2016, 03:46:57 pm
content: Thank you much TimFoxUnfortunately this B-B datasheet shows only the later 5 pin Surface mount. The 8 pin DIL package is obsolete butone should be able to the pin out. I'm planning to determine the pinout using my multimeter...73

author: drussell
author_rank: Super Contributor
timestamp: December 30, 2016, 04:40:15 pm
content: EDIT:Now I see that the link TimFox posted is the even-earlier 1999 version from BB, not the 2000 versions I've listed here from right when TI acquired BB.Even the earlier PDF version of the datasheet from 2000:http://www.mikrocontroller.net/attachment/23987/INA138.PDFmentions only the SOT23 package. Same for the old version of the 139:http://www.datasheetarchive.jp/dl/2c6343078c630d41d4405c3852858fe7e182b2/P/sbos181What is theexactnumber on the chip? Does it have a suffix like 138D or something? Perhaps searching for the exact one will yield another datasheet.I might have it in my paper-copy databook collection from the 80s-90s, I will see if I can dig up one for you later this afternoon and scan it. If it had been TI or Linear, I would definitely have it but it would still be Burr Brown back then, I think all my TI books are pre-BB and not sure that I have any actual BB books, though I will take a look for you...

author: KhronX
author_rank: Frequent Contributor
timestamp: December 30, 2016, 04:41:05 pm
content: How about this one? It contains the SOP-8 pinout; usually the pinouts homologous to the through-hole parts.http://shpat.com/docs/texas/ina138-q1.pdf

author: outremer
author_rank: Contributor
timestamp: December 30, 2016, 05:02:05 pm
content: Thank you all,To drussel : The exact print on the chip is INA138P.To KhronX : I have already this document and will probably bet on it.Even the seller from whom I bought the last lot of 10 was unable to find the real pinout.best 73s, regards & happy, healthy & prosperous 2017.

author: rsjsouza
author_rank: Super Contributor
timestamp: December 30, 2016, 05:11:08 pm
content: Quote from: KhronX on December 30, 2016, 04:41:05 pmI saw the same pinout in a google search for images. I suspect that is the closest that can be found.While searching I ran intothis pretty cool application notefrom Burr Brown about OpAmps...

author: drussell
author_rank: Super Contributor
timestamp: December 30, 2016, 06:05:22 pm
content: I would be willing to bet that the automotive grade -Q1 in the TSOP isNOTthe correct pin-out... That chip didn't come out until 2003 and would be a TI version... It's pin-out looks nothing like the typical BB instrumentation amps...Give me an hour or so to dig out my boxes of data books and I'll bet I can give you a pretty good guessInteresting version of that chip, you have there... A very rare bird, indeed!

author: wraper
author_rank: Unknown
timestamp: December 30, 2016, 06:23:16 pm
content: Quote from: drussell on December 30, 2016, 06:05:22 pmMaybe because it is not a "typical BB instrumentation amp", there is no gain resistor and it has current output.QuoteSo what? Pinout is driven by bond pad layout on the silicon die. Pin order perfectly matches SOT23-5 in reverse.

author: drussell
author_rank: Super Contributor
timestamp: December 30, 2016, 07:21:59 pm
content: Quote from: wraper on December 30, 2016, 06:23:16 pmI misspoke, I really meant typical diff amp... Even though these are all part their "INA" "instrument amplifier" series, the "real" instrumentation amps are combinations of amps usually in a 16 pin package...I dug through my data books and the latest in pretty much everything I have is 1995-6... The '95 BB book only goes to INA131..Murphy at it again... IthinkI have some TI books from 99/00 somewhere but they aren't in those boxes, just older TI, National, Linear and some Motorola DSP stuff and application notes. There must be another box of big yellow books hiding around here somewhere.In any case, I found copies of the 96/97 BB and the 98 BB books online, and the 138 isn't in either of those either, so the INA138 must have been first released right as they were being morphed into TI in early 99....QuoteWell, obviously... and, indeed, I had misrecalled the pin-outs anyway, I thought the power was more in the middle, though it seems the VCC is often on pin 7 on the diff amps because they put a compensation pin up at pin 8...Regardless, I think it probably follows ones like the INA117 very closely, since before they created the 138 specifically for current sensing, the 117 is the kind of chip you would use in that situation... It even handles common-mode signals up to +- 200vSo, all in all, it may well be the same as that 8-pin -Q1 version, however, if hooking it up with VCC on 8 and GND on 4 and probing the output doesn't seem to work, try 7 for VCC like the INA117 is... BB would likely have originally made it similar to that since it is basically a 117 with an output transistor... and probably no external access to the inboard side of the input resistors for reference use on 1 and 5 like the 117 has...Luckily it is basically just an op-amp so once you find the power pins, you can figure out what everything else does fairly easily... Especially with a 'scope, if you have one...http://www.ti.com/lit/ds/symlink/ina117.pdf

author: outremer
author_rank: Contributor
timestamp: December 31, 2016, 02:16:48 am
content: Hi drussel !As soon as I receive the rare birds I will test them with my multimeter, function generator and scope.The items left Santa Clara (CA) yesterday and should show up in the Caribbean in 2 or 3 weeks. So I'll keep you informed.Thank you73s FM5GB

author: outremer
author_rank: Contributor
timestamp: January 23, 2017, 05:11:44 pm
content: Hi All,I received the IC's last week and I am stuck in determining the pinout.So far I found the three NC (no connection pins) as being pin 1, 5 & 8 using my VOMI attached the inner layout and pinout given for the SMD TSSOP8 model which is still in production.So obviously the SMD package does NOT correspond to the DIL8 thruhole package.So how could I determine the other pins, especially V+ and ground pins with a non destructive method ? (I have function generator and scope available)All searches to find TI or BB datasheet for the rare bird remain negative.Thank you much for any help and best regards.Phil FM5GB

author: drussell
author_rank: Super Contributor
timestamp: January 23, 2017, 08:51:27 pm
content: Quote from: outremer on January 23, 2017, 05:11:44 pmLike I said before above, I would expect it be the same pin-out as the INA117...2 = -In (Vin-)3 = +In (Vin+)4 = V- (GND)6 = Vo (OUT)7 = V+...which matches what you seem to be observing with your multimeter tests.Quote from: drussell on December 30, 2016, 07:21:59 pm

author: outremer
author_rank: Contributor
timestamp: January 26, 2017, 03:57:27 pm
content: Hi drussel !Many thanks for your help; the pin out you gave me is the good one. The piece works.Best regards!Phil, FM5GB