Path: csiph.com!weretis.net!feeder6.news.weretis.net!news.glorb.com!peer03.iad!feed-me.highwinds-media.com!news.highwinds-media.com!spln!extra.newsguy.com!newsp.newsguy.com!drn From: Winfield Hill Newsgroups: sci.electronics.design Subject: Re: noise in instrumentation amplifier Date: 3 Nov 2016 10:58:37 -0700 Organization: Rowland Institute Lines: 22 Message-ID: References: <45614b8824e86ebb44aee5912bcfa0966f41b39e@news.nemoweb.net> NNTP-Posting-Host: pf4e18c440a660a6ae43ef066c8a4cf5da8330e8dacce2981.newsdawg.com User-Agent: Direct Read News 5.60 X-Received-Bytes: 1353 X-Received-Body-CRC: 1730806686 Xref: csiph.com sci.electronics.design:433686 George Herold wrote... > Spehro Pefhany wrote: >> On Thu, 03 Nov 16, the renowned val wrote: >> >>> I have a basic instrumentation amplifier made with >>> three MAX 44245 op amps. >My problem is that I have >>> too much noise in the 50 to 100 kHz bandwidth ... >> >> If you look at the datasheet, that op-amp has a strong >> peak of noise around 40kHz (130nV/rtHz) vs. less than >> 50nV/rtHz at 1kHz (still pretty noisy). ... > > 50 nV/rtHz, Yuck! And they call it a low noise opamp. Did y'all notice it's an auto-zero amplifier, to get its 7.5uV Vos max spec? That means it has input switches running, with charge injection, etc. -- Thanks, - Win