modern low noise linear regulators (through hole) (help choose :)) - Page 1
Forum section: electronics / projects

author: ftransform
author_rank: Frequent Contributor
timestamp: January 11, 2013, 02:16:05 pm
content: So I am interested in finding a low noise positive linear regulator, a positive version of this device.http://www.ti.com/product/tps7a3301This device has very nice specifications and it is available in a TO package but I can't seem to find as ballpark positive counterpart which regulates positive voltage.Can anyone help? I've spent several hours trying to find a similar part so I figured I would ask. I assume it must exist because well, positive voltages seem to be more popular then negative voltages.IF you guys care to list other low noise through hole parts in this thread I'm sure others would appreciate it.I guess it does not make sense to go through hole with this low noise stuff but I am still curious.

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: January 11, 2013, 02:39:08 pm
content: Hi,Have a look at the LT3080ET.http://www.linear.com/product/LT3080Jay_Diddy_B

author: ftransform
author_rank: Frequent Contributor
timestamp: January 11, 2013, 03:19:14 pm
content: Quote from: Jay_Diddy_B on January 11, 2013, 02:39:08 pmAh how could I have missed that. The noise is very close to the other device so it looks like a good choice. This was in daves video iirc, I just did not think of it as a low noise part.I was searching for "low noise" and ultra low noise and low-noise and ultra-low noise and stuff like that. I forgot "low output"

author: ftransform
author_rank: Frequent Contributor
timestamp: January 11, 2013, 04:20:28 pm
content: Linear's website is much nicer imo. I found the following candidates:http://www.linear.com/product/LT1965http://www.linear.com/product/LT3080http://www.linear.com/product/LT1963Ahttp://www.linear.com/product/LT1764Ahttp://www.linear.com/product/LT3083

author: ftransform
author_rank: Frequent Contributor
timestamp: January 11, 2013, 06:35:47 pm
content: http://www.linear.com/product/LT1965http://www.linear.com/product/LT3080Seem to be the two candidates. Which one do you think is better?It seems that the 1965 has half the output noise at 20uv/rms, according to the graph, which is not provided for the lm3080 (which lists a flat 40uvrms value for a 1 amp load, with no indication of how it will perform with a 100ma load). And oh boy would this part be great if you froze it (check out the temperature vs ripple, goes way up as you cool it (as opposed to the lm3080).What do you think is a better choice? It seems to me that the LT1965 is the winner (the fixed version has more noise then the adjustable version, wtf?)Can anyone help me understand this? Check out figure RMS Output Noise vs Load Current (10Hz to 100kHz) on page 10.]Lt1965 also has better ripple rejection on higher frequencies but lower then the lt3080 on lower frequencies.

author: CarlG
author_rank: Regular Contributor
timestamp: January 12, 2013, 11:34:57 am
content: how about thetps7a4700? It's on the same page you linked to in your first post, if you scroll down to the parametrics table.I haven't checked the LT parts, they're usually good choice though.

author: ftransform
author_rank: Frequent Contributor
timestamp: January 12, 2013, 01:36:14 pm
content: Quote from: CarlG on January 12, 2013, 11:34:57 amThat is really nice but it is not available in through hole. The surface mount parts are much higher performance. That package seems particularly unfriendly though.