I want to use LM78xx voltage regulators for various projects. I want to know in general, how should I choose a correct value for input and output capacitors of LM78xx family when I want to change DC to DC (without a need to think about the reservoir cap in AC to DC applications)?
I have done a quick research and I found that various vendors and people recommend different values:
Fairchild 0.33 0.1
KEC 0.33 0.1
National 0.22 0.1
Texas 0.33 0.1
ST 0.33 0.1
MCC 0.33 0.1
Web1 10.0 1.0
Web2 100 10.0
Web3 100 0.1
Web4 10.0 10
What are the consequences of choosing large input and output capacitors?
I have seen some people say too big a capacitor on output has detrimental effect on transient response. But how and when?
I have also seen that people say too big an input is not able to damp oscillation if high frequency impedance of cap being too high. But What if I use a big (3300uf) low or ultra low ESR electrolyte parallel to a metalized film capacitor like 473j100? Isn't the metalized film capacitor with ultra low ESR taking care of high frequency oscillation? While the big 3300uf cap providing a reservoir?
If it is ok to use more than 100nf for output caps, and 330nf for input caps do you you think adding several low ESR metalized disk caps in parallel which lowers the ESR value further is going to make it more robust against high frequency oscillation? Assuming I don't mind wasting several bucks for caps!
I have heard that Low Dropout regulators are sensitive to too low or too high ESR. Is LM78xx considered an LDO? I think it is not. But I have seen some websites are listing them as LDOs.
Please bear in mind that I don't mind about the high losses, heat problems and other sort of problems. I only want to know about the caps value.
I'd be thankful if you could elaborate on these questions as much as you could.
Thank you in advance.