A Double-Isolated DC–DC Converter Based on Integrated ${LC}$ Resonant Barriers

This paper presents a double-isolated dc-dc converter exploiting integrated LC galvanic barriers. The converter consists of only two dice both fabricated in a 0.35- $\mu \text{m}$ BCD technology with a thick-oxide back-end for 5-kV galvanic isolation. It uses a novel architecture to transmit power and the control feedback signal across two double isolation barriers, which are performed by integrated isolation capacitors and transformers. A resonant mode operation for the isolation networks is exploited to boost efficiency with respect to traditional converter schemes based on series-connected isolation components. Measurements of the dc-dc converter at 3.3-V power supply demonstrate 100-mW dc output power with a power efficiency of 16.8% at a regulated output voltage of 3.3 V.