Tool/software:
Hello!
I would like to check my understanding concerning the resistor R5 and R7 in this reference design.
1) these resistors are used to reduce the gain to 101 compared to the open-loop gain. The reference sheet says this is for stability. Does this stability refer to against oscillations or against fluctuations in the op-amp gain? If the latter, isn't it the case that the op-amp is inherently insensitive to the drift of the open-loop gain because it is to large?
2) compared to not using the feedback pin (pin3), now the voltage in the inverting terminal is sensitive to the op-amp output, and so the voltage at the non-inverting input. As the result, the actual output voltage cannot be predicted (at least without the transfer function of the PWM comparator), and needs to be adjusted with a potentiometer for the actual desired output value. Is this correct?
3) will there be any issue using TL494 with R5 shorted and R7 left open (i.e. not using feedback pin), (since the circuit is getting a global feedback from Vout into the non-interting input terminal and the output voltage is well-defined by Vref and the op-amp)?
