Power Electronics Europe Issue 4 - November 2022

18 POWER MODULES www.vicorpower.com Issue 4 2022 Power Electronics Europe www.power-mag.com ZVS/ZCS, SAC DC-DC (VTM2919P35K01A5S), which accepts a line voltage from 13.4 to 35V and outputs a fixed load voltage 1/32 of the input, ranging from 0.42 to 1.1V. Its maximum ambient efficiency is specified at 91% in a package size of 29.2 19.0 4.9mm weighing 13.3g. The four DC-DCs have been designed using a redundant system architecture containing two identical parallel powertrains with fault tolerant control to meet single-event-effect (SEE) requirements. To reduce manufacturing costs, the parts have been packaged in a plated, epoxy-moulded resin BGA with excellent thermal conductivity, branded as SMChiP™ , compatible with standard surface-mount, pick-and-place, and reflow assembly processes (Figure 3). The DC- DCs are EAR99, specified from –40 to 125°C and offer various overvoltage, short-circuit current, undervoltage, and thermal protection features. The target bespoke input/output options can also be ordered. To highlight the superior densities offered by the new rad-tolerant DCDCs, Figures 4 and 5 compare their relative sizes with existing space-grade switching POLs and isolated DCDCs respectively. The power density of each convertor in W/in 3 , its efficiency in % and current density in A/in 2 , have been annotated in blue, orange, and red respectively. A range of efficiencies are typically specified for different load conditions and the maximum values from each datasheet are displayed below. The new, rad-tolerant, COTS SAC DC- DCs are an innovative and enabling technology for NewSpace applications. When compared with existing qualified converters, they deliver major increases in output power, density, and efficiency in a smaller volume and lighter form-factor. Regulated voltages are significantly cleaner with less bulk decoupling. Parts will have heritage from next year and evaluation boards are available to help you de-risk future mission needs. The FPA is a major advance to reduce the I2R distribution losses handicapping existing intermediate power architectures. A low- current, factorized bus allows much more freedom to place the BCM® and PRM away from the typically-congested load area. A modular, 100V PDN solution now exists offering SWaP benefits to supply the latest, ultra-deep-submicron, space-grade semiconductors. The VTMs provide high- performing ratiometric DC-DCs and when combined with a PRM, enable a complete closed-loop FPA exploiting the efficiency advantages of a high-voltage factorized bus (Figure 6). This article was originally published by EDN. Figure 4: This diagram compares space-qualified switching POLs with the VTM2919 DC-DCs. Figure 5: This diagram compares space-qualified isolated DC-DCs with the BCM and PRM DC-DCs. Figure 6: A modular 100V power-distribution solution now exists for spacecraft avionics. total-dose is 50kRad (Si) with SEE and other reliability data to be released later this year. Datasheets are available and