I didn't quite understand most of that, but my point is that I got the circuit from the part's page on linear.com and didn't touch it. The big question is: Is the circuit good enough as it is now? I mean, will it oscillate or do errors..?
Also, what about replacing our MOSFET with another one... namely: FDZB33N25. It is modern and has SMD version.
I made R9=5k and the result is: for 5v output voltage, 6.27v pre-regulator voltage. Same result when I make a resistor divider at the gate of Q2. Also can we replace C16 with an already used value like 1n or 10n?
One more thing, we have a separate supply for the op-amps and other stuff like MCU\ADC\DAC... right? so these stuff are all must be powered from the isolated supply that has the true GND (which is OUT+ terminal) as its negative terminal and thus supplies positive voltage to the MCU and other stuff. My concern is about everything else like LCD, other ICs,... etc. Should all of them be powered from the Isolated one or just the ones that has relationship of the power controlling loops? in this case, some ICs like external ADC\DAC will be I2C or SPI... which might cause an issue right?
We will end up with 2 linear supply ICs (LM317 for example): one is powered from battery positive terminal (after protection) which is labeled as "IN" in the spice file, and has the battery negative as its negative (called OUT-)... While the other one is power from the isolated supply's positive terminal and the GND as its negative terminal.
^ Which is for which?
I forgot how measuring and sensing of the output voltage and current work in this topology!! I tried to remember but failed with it, the only thing I do remember is the transistor Q3 is used for anti-windup function... probing voltages didn't give me any clue, the V_sense one has the proper 0.2v value while current sensing pin of the opamp gives odd values like uV! how does it sense output voltage and current? and exactly how can I read them into the MCU?
thanks!