I require a 3.3uf capacitor in a 30 VDC environment for three different purposes:
- decoupling of precision ADC or DAC;
- input to a regulator (linear, switching, LDO); and
- output of any regulator for the purpose of ripple reduction.
I can either use an MLCC (Multi-Layer Ceramic Capacitors) or Tantalum capacitor. I know the main drawback of MLCCs compared to tantalums is that the effective capacitance is reduced by applying DC voltage to them. So I set off to find suitable capacitors with voltage ratings of 50 VDC (to be on the safe side). I'm looking for 3.3uf Tantalum and MLCC whose effective capacitance is 3.3uf @ 30VDC.
Tantalum: 3.3uf 50 VDC costs about $2.00
MLCC 10uf 50 VDC X7R dielectric with effective capacitance of 3.3uf @30VDC costs about $0.70
Is there any reason that I might have missed which would warrant using the pricier Tantalum instead of the MLCC for aforementioned three purposes (exclude the case where a MLCC would make a regulator unstable due to the extremely low ESR) ?