enter image description here

hello. First, this is not my circuit. Second, I'm newbie student. I just started studying electronic circuit two weeks ago.

I'm just playing with this Circuit. just poking around.. I have some questions. can you guys help me?

enter image description here enter image description here

in this case, I can see weird graph in oscilloscope. (channel B connected to 'c'in circuit and ground)

enter image description here

is this graph right? I thought this graph should look like sine graph...isn't it?

  • 1
    \$\begingroup\$ Welcome to Stack Exchange. What do you expect the circuit to do? \$\endgroup\$ – Brian Carlton Nov 20 '18 at 2:14
  • \$\begingroup\$ well, I thought this circuit is amplifier, so ... I think it should amplify my input voltage...and I just curious about that graph \$\endgroup\$ – Queen Ellery Nov 20 '18 at 2:16
  • \$\begingroup\$ Try a 5 mV (or maybe 5 uV) peak-peak input, what results do you get? \$\endgroup\$ – The Photon Nov 20 '18 at 2:28
  • 2
    \$\begingroup\$ The amplification of this circuit (an operational amplifier) is enormous – 100.000 or so. You had to apply external resistors to limit it. What you see is clipping (the tops of the sins are higher than the supply can deliver.) \$\endgroup\$ – Janka Nov 20 '18 at 2:30
  • \$\begingroup\$ well, Thanks Janka. where do you recommend me to apply resistors? \$\endgroup\$ – Queen Ellery Nov 20 '18 at 3:14

Assuming 1mA thru the current source, split into left and right sides of the input diffpair, that 0.5mA making 'reac' be 52 ohms, the gain will be 15,000 / (52 + 52) or about 150X.

This answer has a similar circuit.

Learning electronics


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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