Is it possible to output voltages in the range of kilovolts and current of atleast >1mA using an input of <10V on a consumer electronics op amp such as IC 741? If not, then why?

  • 2
    \$\begingroup\$ Anything is possible in SPICE-world. \$\endgroup\$ Sep 18 '14 at 18:04
  • \$\begingroup\$ @SpehroPefhany - I assume you are talking about Spice World the movie ;-) +1 \$\endgroup\$
    – gbulmer
    Sep 18 '14 at 18:11
  • \$\begingroup\$ @gbulmer Scary (spice). \$\endgroup\$ Sep 18 '14 at 18:14
  • \$\begingroup\$ The simple answer is "No it can't". It might be easier to explain why it can't if you explain "What caused you to think that an OpAmp could output a voltage higher than its power supply?" \$\endgroup\$
    – gbulmer
    Sep 18 '14 at 18:14
  • \$\begingroup\$ @gblumber I am not really an engineer or anything, just a hobbyist (for now). The wiki page for opamps says that it can has a gain of hundreds of thousands times... You can see where this is going. \$\endgroup\$
    – AvZ
    Sep 18 '14 at 18:18

No it isn't possible. Your op-amp can't produce an output any higher than the power supply voltage you connect it to. Those very high gain values you'll find on a typical op-amp's datasheet are only possible when its given very tiny input signal voltages to amplify. For example if the gain is 100,000 and the input voltage is 0.1mV (0.0001V) then the output would be 10V (assuming the you've given the op-amp at least a 10V power supply). But if the input signal voltage is 1V and the gain and power-supply voltage are the same, then you'll still only get 10V out.

For the technically inclined - yes I'm ignoring the fact that op-amps are rarely, if ever, used open-loop and I'm assuming an op-amp with perfect rail-to-rail output swing.

  • 1
    \$\begingroup\$ You're ignoring op-amps that can swing beyond their supply such as the ADA4858-3. ;-) \$\endgroup\$ Sep 18 '14 at 18:48

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