Single Supply to dual supply circuits, which one's the best? - Page 1
Forum section: electronics / beginners

author: josechow
author_rank: Contributor
timestamp: June 07, 2016, 12:54:22 pm
content: Hey All,So I have been trying to wrap my head around single to dual supply conversions. I need to supply a balanced line driver for audio purposes down a 25 foot cable. below are three dual supply arrangements I have seen. Based on the limited research I was able to conduct on google, arrangement 2 has the best noise rejection characteristics for my needs. Am I correct in my assumptions? Is there a better method that doesn't involve switch mode regulators or batteries?dual suppliesbyDavid Deininger, on Flickr

author: danadak
author_rank: Super Contributor
timestamp: June 07, 2016, 01:56:58 pm
content: You can always use a linear regulators thru out or a switcher front endto linear regulators for the supply rails. Pay attention to the linear regulatornoise rejection if you use a switcher front end.An example of one possibility -http://www.ti.com/product/DRV135Regards, Dana.

author: Zero999
author_rank: Super Contributor
timestamp: June 07, 2016, 03:27:59 pm
content: I don't see why you need a dual supply for this. It's possible to do this with a single supply.What are your amplitude, power and gain requirements?

author: josechow
author_rank: Contributor
timestamp: June 07, 2016, 04:20:01 pm
content: Quote from: Hero999 on June 07, 2016, 03:27:59 pmI intend on using the DRV134 or DRV135 as Dana pointed out without me saying what device I intend to power with the split supply. From what I could gather from the datasheet for the DRV134, I need a dual supply in order to appropriately bias the opamp. Or do I just use the configuration 1 in the graphic I provided, connecting 12volt to +V, 6volt to GND, and Ground to -V ?Amplitude (2Vpp), Unity Gain, Power requirements to feed audio signal from DRV134 through 25 foot cable to a INA134 differential line receiver.

author: Zero999
author_rank: Super Contributor
timestamp: June 07, 2016, 07:20:23 pm
content: When I posted previously, I couldn't see the schematics because I was at work and they were blocked by the firewall. Why not attach them to the post so that doesn't happen?Arrangement 1 probably won't work very well. The 6V regulator will only be able to source current and any fluctuations in the supply voltage will be passed through to the output.Arrangement 2 will only work if the negative 5V supply is a charge pump or buck converter. It will not work with a negative linear regulator which which require a negative input voltage.Arrangement 3 will work but why not omit the 12V regulator and put a filtering capacitor across one of the resistors in the potential divider before the op-amp? The input and output signals should be AC coupled using two non-polarised 10uF capacitors: two 22uF electrolytic capacitors connected back-to-back will do.

author: josechow
author_rank: Contributor
timestamp: June 07, 2016, 07:33:22 pm
content: Quote from: Hero999 on June 07, 2016, 07:20:23 pmI'm still learning the forum, since everyone im apart of is slightly different.Quote from: Hero999 on June 07, 2016, 07:20:23 pmThanks! I have a 24volt source coming to the circuit to power the led drivers. I didn't add the extra components because I didn't want to draw them into the quick schematic. I will order the parts and give arrangement 3 a try.Again, thanks for the response!