I need the negative voltage for my OPAMP and I use the LM2664 inverter. I have a very limited space available on my PCB. Is it OK to replace the electrolytic capacitors with the ceramic ones?
1\$\begingroup\$ There is a selection on capacitor selection in the datasheet, but ultimately it looks like it's happy with low ESR, so ceramic caps should be ok. \$\endgroup\$– ColinDec 14, 2017 at 9:55
\$\begingroup\$ Strange, but where do you find ceramic caps that are smaller than elec. caps for the same capacitance. \$\endgroup\$– Marko BuršičDec 14, 2017 at 10:07
\$\begingroup\$ @MarkoBuršič for example here uk.farnell.com/c/passive-components/capacitors/… \$\endgroup\$– 0___________Dec 14, 2017 at 10:10
\$\begingroup\$ Why invent warm water, if they provided the EVAL board with all details for caps and design. \$\endgroup\$– Marko BuršičDec 14, 2017 at 10:36
I've had a look through the datasheet and all it seems to say about the capacitors is that they must have a low ESR. I can't find anywhere that it specifies a minimum ESR or states that they must be electrolytic.
Therefore, I think you can safety use ceramic capacitors as these have a very low ESR.
Hypothetically, if the datasheet did require a minimum ESR (as some devices do), you could still use a ceramic capacitor instead. All you'd have to do is place a small resistor in series with the ceramic capacitor (around 0.5 ohms, or whatever value the minimum is in the datasheet).