SNOA930C March 2015 – May 2021 LDC0851 , LDC1001 , LDC1001-Q1 , LDC1041 , LDC1051 , LDC1101 , LDC1312 , LDC1312-Q1 , LDC1314 , LDC1314-Q1 , LDC1612 , LDC1612-Q1 , LDC1614 , LDC1614-Q1 , LDC2112 , LDC2114 , LDC3114 , LDC3114-Q1
Figure 2-14 shows how the individual turns of an inductor have a certain physical area and are separated by a dielectric; this produces a small parasitic capacitor across each turn. At a sufficiently high frequency, signals find it easier to simply jump across the distributed parasitic capacitance rather than traverse along the spiral winding of the trace. The frequency where these two paths are matched is self-resonance frequency, which is represented as ƒSR or SRF. Because the parasitic capacitance is not very stable, it is recommended to keep the sensor frequency below 75% of the SRF.