LFC Semiconductor’s new SAϕIC™ technology addresses all these shortcomings and enables its use in numerous applications including those that demand adherence to very strict system timing budgets.
This is achieved by eliminating the requirement of a PLL to effect the modulation (refer Figure 2). The modulation is achieved by the reconstruction of the input signal with a precise but dynamic phase shift over the modulation cycle. The phase shift amount is controlled and has been optimized to provide the maximum EMI suppression with the minimum phase shift.
Mathematically, the effective Frequency Modulation is governed by the relation between the instantaneous frequency and phase change given by:
finst = δ(ϕ) / δ(t) where finst is the instantaneous frequency
δ(ϕ) / δ(t) is the rate of change of phase.
By carefully controlling the manner in which the phase of the input signal is modified, the peak energy can be effectively distributed over a wider frequency band. The comparative advantage is tabulated in Table 1.
Figure 2 – SAϕIC™ Implementation of Active EMI Management