Can I replace higher capacitance value MLC capacitor in Sallen-Key topology filter with 2-3 lower value capacitors in parallel (with total capacitance equal to replaced cap)? I tried it in TINA-TI and AC Transfer characteristics are identical. Are there any contraindications to this?
The filter is 0.6..6.4Hz band pass. I started designing it using application report with basic equations, then did a lot of changes to adjust transfer characteristics. Changes include using capacitors with values not available on market.
Best Answer
Yes, as long as the parallel capacitances sum to the capacitance of the replaced capacitor there is no difference in the circuit. This is typically done in order to get a non-standard capacitance value out of standard capacitance values. For example, if you need \$8.6\mu\$F then you can put two standard \$4.3\mu\$F capacitors in parallel to get it since \$8.6\mu\$F is not a standard value.