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Thank u SunnySkyguy.
I'm aware that this circuit may have stability problem. As a result, I also checked voltages with oscilloscope to ensure stability.
Can you explain me more about biasing of FETs. I design this using a famous circuit for precision current sink/source.
Are you mean Voltage...
Actually, there are two 10 ohm resistors in collector of Q16 and Q6 for check point. I used them only for measuring output current of these transistors without breaking connections. Reading their voltage says me that current of Q16 and Q6 is 0.2mA and approximately zero respectively.
I changed...
Sorry. There is a mistake here. In the schematic which uploaded here RL=10k ohm while I tested my circuit with RL=1k ohm. So, when voltage across RL is 0.2 volt it means 0.2mA passes through it. Similarly 8.3mA passes through R2!
It is a simple KCL. There is no way for current except pin 2 of...
I mean inverting and non-inverting signal inputs, not supply pins.
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Thank u Brain.
But I'm sure about my measurements. I measured voltage across R2 and RL and they are about 8.3 and 0.2 volt respectively. Op-amp may damage. But It is new! This is the first time I use it...
Hi all;
I recently used TL072 op amp in my desgn. This op amp is J-FET input and according to its datasheet, its input current should be in range of pA. However, I measure 1 to 8 mA current in both + and - pins of the IC. I really confused that how it can possible !!?
The design is a...
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