Finally, someone did this - no feedback resistor adjustable voltage regulator - Page 1
Forum section: electronics / general

author: daqq
author_rank: Super Contributor
timestamp: July 09, 2019, 06:33:49 am
content: Finally,http://www.ti.com/lit/ds/symlink/tps7a47.pdfJust connect the appropriate pins to GND, adjustable by .1V steps, no obscure E192 value resistors to get that sweet sweet 3.3V and the pin layout is very reasonable. Thanks, TI!

author: Ice-Tea
author_rank: Super Contributor
timestamp: July 09, 2019, 06:54:38 am
content: Enpirion/Altera/Intel has done it a long time ago

author: tggzzz
author_rank: Super Contributor
timestamp: July 09, 2019, 07:17:49 am
content: A more accurate title would be "noexternalfeedback resistor".

author: Circlotron
author_rank: Super Contributor
timestamp: July 09, 2019, 07:48:16 am
content: Let's see who will be the first to make a class A digital input audio power amplifier out of it. Rough as guts of course, but doable.

author: EEVblog
author_rank: Unknown
timestamp: July 09, 2019, 08:06:07 am
content: 4uV RMS noise you say...

author: Warhawk
author_rank: Frequent Contributor
timestamp: July 09, 2019, 08:22:19 am
content: What about a simple curve tracer?

author: daqq
author_rank: Super Contributor
timestamp: July 09, 2019, 08:24:18 am
content: QuoteNot sure it's possible with this one (certainly not as the main purpose of the device). See the NR pin, where a 10n cap must be placed to assure stability. At a quick glance it creates an RC filter for the "DAC", so the "bandwidth" of it is limited to ~1kHz as I understand it. Pretty cool idea though.QuoteDidn't know that. Great to know for future reference, thanks!QuoteThat's not bad though, is it?

author: VK3DRB
author_rank: Super Contributor
timestamp: July 10, 2019, 02:02:30 am
content: Nice, BUT two issues not mentioned: Cost and availability.This chip is expensive. If you are designing a cost sensitive, high volume product, you would probably avoid this part. Else, it could be ideal for some applications.Regarding availability, OK, TI is respectable and it might not be too big an issue, but I try to avoid parts where there is no alternative source for the same form, fit and function if a products is going to run for several years. Sometimes of course, this cannot be avoided of course; for example microcontrollers or power management ICs.

author: KE5FX
author_rank: Super Contributor
timestamp: July 10, 2019, 02:08:22 am
content: I like the MAX8902A for this reason. 1.5V/1.8V/2.0V/2.5V/3.0V/3.1V/3.3V/4.6V/4.7V available from two selection pins.Decent PSRR and noise specs, nothing world-beating but it makes a good jellybean part.

author: KE5FX
author_rank: Super Contributor
timestamp: July 10, 2019, 03:23:47 am
content: Quote from: blueskull on July 10, 2019, 02:11:02 amNo kidding. These days 26 weeks is a GOOD lead time.

author: floobydust
author_rank: Super Contributor
timestamp: July 10, 2019, 04:00:31 am
content: I can't get excited about it. It looks like it's good for about 1W. Thermal design hands you off to a report using Jedec "test board" or infinite heatsink, no mention of copper thickness or number of layers etc. You need a real 50uF ceramic output capacitor to get the good specs. $5 ea and $2.50 ea on a reel.