0
\$\begingroup\$

I'm looking OpAmp which could be powered from dual power supply greater than + - 36V. Current transformer provides 36,9V. And LM358 on a single supply could work up to 36V. I'm looking something what could be work on dual supply up to 40V. Any suggestions? Thank you

\$\endgroup\$

closed as off-topic by ThreePhaseEel, Voltage Spike, Daniel Grillo, Dmitry Grigoryev, dim Nov 23 '16 at 11:12

This question appears to be off-topic. The users who voted to close gave this specific reason:

If this question can be reworded to fit the rules in the help center, please edit the question.

  • \$\begingroup\$ Questions seeking recommendations for specific products or places to purchase them are off-topic as they are rarely useful to others and quickly obsolete. Instead, describe your situation and the specific problem you're trying to solve. \$\endgroup\$ – Wesley Lee Nov 21 '16 at 9:45
  • \$\begingroup\$ Try searching Apex they have pretty large range of HV op-amp, expensive thouh. \$\endgroup\$ – carloc Nov 21 '16 at 10:55
  • \$\begingroup\$ Linear has several listed here. \$\endgroup\$ – EM Fields Nov 21 '16 at 12:19
  • \$\begingroup\$ Yeah I've used the linear LT6090 \$\endgroup\$ – George Herold Nov 21 '16 at 15:51
0
\$\begingroup\$

If it's a conventional current transformer and has an internal burden then applying an extra external burden resistor will lower the output voltage and give you more options on the choice of op-amp. Alternatively just use a potential divider to reduce the voltage to a more acceptable level.

PS asking for device recommendations is the quickest way to get a question closed. read the rules: https://electronics.stackexchange.com/help/on-topic

\$\endgroup\$
  • \$\begingroup\$ Thank you for a tip, I'll keep it in mind. I was just struggling to solve this step. \$\endgroup\$ – Dmitrij Kirikil Nov 21 '16 at 10:12
2
\$\begingroup\$

Don't bother trying to find a +/- 40V op amp, just add a high voltage output stage to your LM358.

enter image description here

See page 8 http://www.ti.com/lit/an/snoa600b/snoa600b.pdf

Edit:

Having said that I did find this: The LM143 which runs up to +/- 40V

http://www.ti.com/lit/an/snva516/snva516.pdf

\$\endgroup\$
  • \$\begingroup\$ This will make circuit much complex just because of this 1V. But it is a solution. Thank you \$\endgroup\$ – Dmitrij Kirikil Nov 21 '16 at 10:11
  • \$\begingroup\$ Using a dual supply you only get +/- 16V (32 V max) on an lm358 so it not just a 1V difference. Your +/- 40V target means you'll need something capable of handling 80V. If you search around you might be able to find a simpler design for the output stage or even an IC with it all built in. \$\endgroup\$ – JIm Dearden Nov 21 '16 at 10:24
  • \$\begingroup\$ FYI: the particular circuit you show is from National's AN-272. The link to that application note in the how-to wiki is dead but AN-272 can be found at ti.com/lit/an/snoa600b/snoa600b.pdf. The circuit is explained on pp. 7-9 (section 5: +/-120V Swing Booster). \$\endgroup\$ – Null Nov 21 '16 at 16:00
  • \$\begingroup\$ Yes, I was confused and thought that it was 36V. Basically I need one op amp to increase 5 to 36 range and other to invert -5 to positive 36V. So supplying ground to VCC and -30 to Vee. works as well. The only one problem how to get 40V range in inexpensive way. :) But I found some solutions already to try and suggestions here needs to be tested as well. Thank you :) \$\endgroup\$ – Dmitrij Kirikil Nov 25 '16 at 16:02
0
\$\begingroup\$

Have a look at the LTC6090, which accomodates a supply voltage of up to 140V (+/- 70V) with rail to rail output swing and generally reasonable specifications all around:

http://www.linear.com/product/LTC6090

\$\endgroup\$
  • \$\begingroup\$ This one good. But very expensive 5$ for one. \$\endgroup\$ – Dmitrij Kirikil Nov 25 '16 at 15:58

Not the answer you're looking for? Browse other questions tagged or ask your own question.