Intersil FGA (tm) Voltage References - Page 1
Forum section: electronics / general

author: mycroft
author_rank: Regular Contributor
timestamp: June 08, 2017, 09:47:23 pm
content: Folks,I searched this forum but could not find information on Intersil FGA Voltage References like X60003http://www.intersil.com/en/products/data-converters/voltage-references/x60003-family.html.There is an article about it "A very high precision 500-nA CMOS floating-gate analog voltage reference"http://ieeexplore.ieee.org/abstract/document/1546213/but from Intersil itself. Have anyone experimented with this technology?Regards.

author: zhtoor
author_rank: Frequent Contributor
timestamp: June 08, 2017, 09:52:47 pm
content: Quote from: mycroft on June 08, 2017, 09:47:23 pminteresting technology, trapping a charge on a floating gate capacitance and using it as a reference,i wonder if something similar could be done with supercaps (at least short terms reference replenished by say an lm399)the noise characteristics could be wonderful, sort of like charging the supercap to the reference voltage, maintaining that level,and switching off the main reference for measurement using a predictable time/temp slope *very* low noise reference formeasurements.regards.Regards.

author: Andreas
author_rank: Super Contributor
timestamp: June 09, 2017, 04:35:56 am
content: Hello,yes of course.I have 2 samples of ISL21009BFB850.In principle they are ideal devices for my battery powered ADCs.But there is one feature which make them useless for my volt-nut applications.There is some kind of "switch off hysteresis".After a short time of power supply interruption (battery change after some days of operation)they start with about 200uV lower voltage.After this it needs days to go back to the previous output voltage.The feature is within data sheet spec of +/- 0.5 mV initial tolerance so I cannot complain.But with other references I am within ppm-Level after 15 minutes warm up time.Diagram:x-axis: time in minutesleft axis temperature in deg Cright axis output voltage in mVreference before switchoff 4999.790 mV restarts at about 4999.6 mVreference after 750 minutes returned back to 4999.770Temperature change is between 25-26 deg C.with best regardsAndreas

author: zhtoor
author_rank: Frequent Contributor
timestamp: June 09, 2017, 04:48:22 am
content: maybe they are designed to be continuously on (like fluke 732).maybe running these with an auto lead acid battery for a year or so make an interesting ref.regards.

author: BravoV
author_rank: Super Contributor
timestamp: June 09, 2017, 04:53:28 am
content: This reminds me of an interesting app note from Intersil that I read while ago.->X-Ray Effects on Intersil FGA ReferencesNot sure if the latest floating gate analog reference technology is still affected by X-ray.

author: Kleinstein
author_rank: Super Contributor
timestamp: June 09, 2017, 07:53:46 am
content: The technology sounds more like a cheap way to get an adjustable (e.g. at factory) low power reference. So good for accuracy but not precision. It won't be low noise, as it has the 1/f noise of a MOSFET.

author: Vgkid
author_rank: Super Contributor
timestamp: June 09, 2017, 02:07:19 pm
content: I haven't looked at the datasheet, but it might be intended more for ratiometric applications.