Summary: Dave explains, shows, and measures a potentially big trap with using high value ceramic capacitors. If your 10uF capacitor really 10uF in your circuit? Those humble X7R caps you think are a “stable” dielectric? think again… Class II and above ceramic capacitors can vary their capacitance drastically with DC bias voltage level and also the applied AC voltage. Links: http://www.murataamericas.com/murata/murata.nsf/promo_dcbias.pdf http://www.avx.com/docs/masterpubs/mccc.pdf http://www.ece.ucdavis.edu/vcl/asap/asap_v1/docs/X7R_C.pdf http://psearch.murata.com/capacitor/product/GRM21BR60J106KE19%23.html http://www.murata.com/products/design_support/simsurfing/outline.html http://www.avx.com/SpiApps Capacitor Tutorial – Ceramics & Impedance The piezoelectric effect demonstrated Forum HERE
