Spur-Reduction Design of Frequency-Hopping DC–DC Converters

This paper presents an inductor current average control (ICAC) method that minimizes the undesirable transient glitches in dc-dc converters using a frequency-hopping pulsewidth modulation control. The analysis in this paper shows that without careful control of the frequency-hopping instant for the dc-dc converters, the transient glitches can be rather large in magnitude and may interfere with the modulated signal to be transmitted from a mobile communication device. The ICAC technique selects the frequency-hopping instant such that the average inductor current is undisturbed when the switching frequency hops. The measurement result shows that the ICAC technique can suppress the transient spurs by 14.1 dB and the voltage of the transient glitches by 65.3%.