What is a voltage-to-current converter

Forum: Analog electronics and circuit technology Voltage-current converter OPV

Hello everyone, I am currently trying to understand the basics of electrical engineering. Now I have a question about the voltage-current converter as an OPV. I just can't figure out why there is electricity at the exit. :-) Am I referring to the lower resistance (output in front of the ground, because the whole potential drops over it and thus current is generated? Without the Rm no current? Why does the RL have no meaning? How can I tap this? Sorry for my non-existent expertise Greetings Michi

There are many circuits, explain which one you mean. In general, the following applies to OPV calculations: input currents are 0 no-load gain is infinite the difference between the input voltages (Vp-Vn) is 0 (in linear operation) With these findings you can calculate most OPV circuits. regards

RL is the top resistance. If it increases, the potential at the inverting input decreases. This increases the input difference and thus also the output voltage. When this has settled, the input voltage difference is again 0. This means that you have a higher voltage at a higher resistor, which means that the current remains the same. Conversely, accordingly, if the load resistance becomes smaller.

Maybe the circuit note from Analog Devices CN-0099 will help you. I don't know what RL and Rm mean in your case, but with a current output you only get current if there is a load (or short circuit). Do you have a schematic example that you are using?

OK. As already said, the difference between the input voltages should be 0. This means that the OPV has to adjust its output voltage so that the voltage drop at Rm (Ia * Rm) is equal to Ue. So you have a voltage-controlled current source. regards

now I still have a question to see if I understand. E.g. with the impedance converter. here the output voltage is equal to the input voltage because the OPV makes Ud = 0 again. However, the voltage source now has a smaller resistance, since the output resistance of OPVs goes towards NUll ...? http://transistorgrab.de/figures/200701211749.jpg

> However, the voltage source now has a smaller resistance, since the> output resistance in OPVs goes to zero ...? that's the way it is! regards

Important rules - read first, then post!

• Use upper and lower case
• Do not insert longer source code in the text, but as a file attachment