New chopper opamp from AD ADA4523-1 - Page 1
Forum section: electronics / general

author: RandallMcRee
author_rank: Frequent Contributor
timestamp: May 20, 2020, 12:18:28 am
content: Lower noise than the ADA4522. Lower bias current, too. Now we need the -2 dual....https://www.analog.com/media/en/technical-documentation/data-sheets/ada4523-1.pdfhttps://www.analog.com/en/products/ada4523-1.html

author: Vgkid
author_rank: Super Contributor
timestamp: May 20, 2020, 12:55:25 am
content: Looks like it will be a nice part.

author: Kleinstein
author_rank: Super Contributor
timestamp: May 20, 2020, 06:29:56 am
content: It is a nice part in some cases, but the low voltage noise comes at the price of a high current noise and high supply current. So it is good for low impedance (e.g. < 10 K) only. At 10 K the ADA4522 may already be the better choice.Due to the high supply current a dual version makes no sense. Already now heat can be a problem when used with a higher supply.

author: RandallMcRee
author_rank: Frequent Contributor
timestamp: May 20, 2020, 03:57:28 pm
content: Hmmm, not sure why you say these things. Input current noise is not optimized for either of these parts and is quite close for both.Second, Iq for a dual seems well within the range of other duals that are in the precision range...as you can see from the selection.

author: Kleinstein
author_rank: Super Contributor
timestamp: May 20, 2020, 04:42:44 pm
content: For high DC precision one wants low temperature gradients and thus low power. So 4.5 mA, especially at higher voltage are a real downside. One would not like 9 mA at some 30 V and thus some 270 mW from a part for the 100nV range. Using 2 chips would be a small price for half the local heating.The ADA4522 is at some 850 µA only and thus about 1/5 the power. Even there the heat is a downside for using the dual version. There could be a small advantage (but also some disadvantage) from having only one frequency in a dual chip. The high current OPs listed are more like low noise, but not precision types.For the current noise, I somehow got wrong data ( ? old data sheed) in my table for the ADA4522. It also has quite some current noise and the cross over is at some 45 K, where the ADA4522 would give similar total noise.

author: awallin
author_rank: Frequent Contributor
timestamp: May 20, 2020, 06:51:26 pm
content: I think I used OPA2188 last time for a PLL where DC-accuracy might be usefulhttps://www.ti.com/lit/ds/symlink/opa2188.pdf(first dated 2011, so 9 year old design?)the AD part has 10nV/C offset while OPA2188 is 30nV/CAD voltage noise seems about half of the OPA2188..

author: RandallMcRee
author_rank: Frequent Contributor
timestamp: May 29, 2020, 06:29:13 pm
content: I ordered some of these (ADA4523-1BRZ) for testing directly from AD. Minimum qty was 100...So about 50 available to interested parties for the same price as I paid, etc.Note: as some of you know it is unfortunately quite inconvenient, not to mention expensive, to send packages to overseas from the US. Ideally if you are in Europe and would like one or more of these indicate if you are willing to send some on to others also in Europe.PM me.Randall (Davis, CA, 95616)

author: macaba
author_rank: Regular Contributor
timestamp: June 05, 2020, 08:33:30 am
content: Crunching the numbers for overall noise in a 0.1-10hz LNA circuit, this looks to be a decent OA on paper:Using LT1007/LT1037 as x1.00 baseline for overall noise, with a 1.5k resistor in the 0.1hz filter (the largest contributor to noise):ADA4528-1: 1.23xADA4523-1: 1.08xAs long as there is no undesirable behavior, the ADA4523-1 would make a good selection for an LNA. Benefit over the other two; it has the addition of datasheet specified EMI filtering behavior.Edit: ADA4528-2 (i.e. 2 amps in parallel with the increased BOM cost of passives): x1.06 [margin of error on this is larger, not entirely sure how to calculate this given the 2 amps share the same 1.5k resistor]

author: splin
author_rank: Frequent Contributor
timestamp: June 26, 2020, 11:17:36 pm
content: Quote from: RandallMcRee on May 29, 2020, 06:29:13 pmRandall, thank you for going to the trouble of making this kind offer. I received mine, as have been those I forwarded to the Netherlands.I appreciate that it can be quite a pain organising group buys like these having to find shipping costs, dealing with customs declarations and endless email exchanges to sort out the details - including agreeing what happens if the items get lost in the post. So thanks again.

author: GL1381
author_rank: Newbie
timestamp: June 03, 2021, 09:48:45 pm
content: Do you still have ADA4523-1BRZ? I need it for a special project but am not able to get it due to part lead time problemThanks,

author: RandallMcRee
author_rank: Frequent Contributor
timestamp: June 05, 2021, 12:11:11 am
content: Quote from: GL1381 on June 03, 2021, 09:48:45 pmI have a few left but Mouser is your best bet. They have some in stock.Randall

author: jbb
author_rank: Super Contributor
timestamp: June 06, 2021, 07:00:21 am
content: Quote from: shodan@micron on June 04, 2021, 12:10:43 pmOne of these parts is not like the others :-)