op amps - Page 1
Forum section: electronics / projects

author: ranganatennakoon
author_rank: Contributor
timestamp: September 30, 2020, 03:34:27 pm
content: Did anyone use "programmable" Difference Amplifier /op-Amp Subtractor IC ? (looks like PGA programmable gain amplifier)

author: ranganatennakoon
author_rank: Contributor
timestamp: October 09, 2020, 03:45:13 am
content: bump !

author: Vovk_Z
author_rank: Super Contributor
timestamp: October 09, 2020, 10:15:59 am
content: It seems not much people.You may try to rename this topic to "Programmable opamps", if there is a possibility - possibly it may help to attract attention.

author: Zero999
author_rank: Super Contributor
timestamp: October 09, 2020, 12:42:00 pm
content: Quote from: ranganatennakoon on September 30, 2020, 03:34:27 pmThere's no point in bumping a thread after less than six hours. You need to be more patient.Are you talking about making a PGA, or buying a pre-made IC?No, I haven't used a PGA before, but I did investigate using the PGA280, as part of a datalogger project, which didn't happen. The reason was because it works over a wide supply voltage range up to ±18V and the gain can be varied from1⁄8to 128, allowing the voltage to scaled both up and down, to suit an ADC.https://www.ti.com/lit/ds/symlink/pga280.pdf

author: KT88
author_rank: Frequent Contributor
timestamp: October 09, 2020, 10:12:31 pm
content: There are resistor programmable difference amplifiers that you could get from the usual suspects...Another category is called programmable instrumentation amplifiers or PGIAs from the same sources. They come with different digital interfaces.CheersAndreas

author: ranganatennakoon
author_rank: Contributor
timestamp: October 09, 2020, 10:25:34 pm
content: Quote from: Zero999 on October 09, 2020, 10:12:31 pmdid u see see my thread ? it Posted on September 30, 2020, 03:34:27 pm. I Bumped because there was no response from anyone.

author: Phoenix
author_rank: Frequent Contributor
timestamp: October 10, 2020, 12:32:54 am
content: Quote from: ranganatennakoon on October 09, 2020, 10:25:34 pmPeople are reading and responding now - and are still confused what you want. Can you give an example of the ICs in question?

author: Zero999
author_rank: Super Contributor
timestamp: October 10, 2020, 03:42:15 pm
content: Quote from: ranganatennakoon on October 09, 2020, 10:25:34 pmSorry, I didn't look at the date!If you don't get any replies, then perhaps it's because you haven't provided enough information. I'm still not sure of what you're asking and you haven't responded to the other points I made.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: October 11, 2020, 09:58:05 pm
content: I'm with Phoenix.Post a (link to) a datasheet of the sort of IC's you are referring to.

author: ranganatennakoon
author_rank: Contributor
timestamp: October 12, 2020, 03:40:39 am
content: I have no idea that is why I posted this thread

author: Hiemal
author_rank: Regular Contributor
timestamp: October 12, 2020, 05:31:24 am
content: Playing charades trying to figure out your question isn't fun.Are you talking about this sort of chip?https://www.ti.com/lit/ds/symlink/ina145.pdf?ts=1602480564269&ref_url=https%253A%252F%252Fwww.google.com%252FIf so it's just a differential / instrumentation amplifier with gain you "program" via two resistors. Some have just one you use.But, again, not sure what sort of question you're trying to pose "has anyone used them before". Yeah, definitely people have. But what are you trying to find out?