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I'm searching for the most cost effective way to supply +/-12V for 12 TL084 op amps. Reading in the datasheet, it seems they have a typical current output (with load) of about 20mA. So, 12 * 20 = 240mA. Assuming that is correct, I only need about 300mA of current draw from the +/-12V supply.

Here are the solutions I've come across:

  • Recom Power - RS6-0512D: This modules takes in 5V and provides +/-12V output. Pretty straight forward but a bit pricy, around 21$CAD.
  • Using 1 TC1044S charge pump per 2 op amps and an external 5V to 12V boost converter for the whole deal. Total cost: 1.45$CAD (TC1044) * 6 = 8,70$. Add around 4$ for the 5V to 12V converter = 12,70$CAD for the whole thing.

Any simple solution I haven't thought of? Are these 2 solutions a standard way to power a bunch of signal processing op-amps? Is it a problem even worth solving with a chip or should I go down the road of implementing this myself? Is there even any advantages to implement this myself?

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    \$\begingroup\$ Asking for recommendations of specific products is not allowed on this site. \$\endgroup\$ Nov 19, 2018 at 15:41
  • \$\begingroup\$ Ok, I'll rephrase the question a bit. \$\endgroup\$ Nov 19, 2018 at 15:43
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    \$\begingroup\$ What i really want to know is not really a specific product but rather if the path I'm looking to take makes sense as I don't really know any other routes. \$\endgroup\$ Nov 19, 2018 at 15:50
  • \$\begingroup\$ Is cost your biggest constraint? Do you have board space constraints area or height? \$\endgroup\$ Nov 19, 2018 at 16:38
  • \$\begingroup\$ Also, how are your solder skills/abilities? \$\endgroup\$ Nov 19, 2018 at 16:43

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One way to tackle this is to implement a boost regulator with two outputs - one inverted, and one non-inverted - such as the TI TPS65130. It's about US$3 / qty. 1 on Digikey, and you'll probably need a few dollars for passives.

TPS65130

Make sure to have decoupling caps (0.1 uF) and bulk caps (4.7 ~ 10 uF) at each op-amp supply pin. If you have low-noise requirements, you can set the boost regulator to +/- 15 V and add +/-12 V LDOs on the outputs.

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  • \$\begingroup\$ Nice alternative. I'll check this out. \$\endgroup\$ Nov 19, 2018 at 17:52
  • \$\begingroup\$ @KévinIsabelle Great! You may want to leave the question open a bit longer (reclick the green check mark) to see if this will work for your application. Also, someone else (perhaps perusing the Unanswered questions) may chime in with alternatives. \$\endgroup\$ Nov 19, 2018 at 18:20
  • \$\begingroup\$ And actually, I've juste checked the price-tag to build this kind of assembly, and it is very close to my solution #2 in terms of price, but more complicated. I see where you were going with the soldering as it is a VQFN package with no leads. Feasible but a bit of a pain for me at prototyping stage. \$\endgroup\$ Nov 19, 2018 at 18:47

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