It’s getting more difficult to design noise-immune circuits for several reasons: An increase in integration of components due to surface-mount technology; new package designs for these integrated circuits that bump up the number of pins per package; and miniaturization of components.
Such features lead to less distance between the conductors, which raises the values of capacitance and inductance per unit length of interaction. Consequently, it increases the induced interference in adjacent conductors.
One remedy is to boost the speed of signal circuits of modern PFs as well as have a large spread in speed, from 1 MHz to hundreds of MHz, and even 1,000 MHz. For example, there are circuits that transmit a signal at a frequency of 48 MHz and at 576 MHz.