The AI datacenters of the future necessitate thousands of Amps of current, resulting in large resistive losses in the PDN. Vertical power delivery (VPD) and/or 48V IBCs built entirely on the package can address this issue, putting extreme demands on the overall power density of the solution. The size of the magnetics is still the biggest bottleneck, dictating the overall converter optimization. We present an Input-Inductor Cascaded Buck (I2CB) topology that minimizes inductor footprints by (i) keeping them on the input side (HV side) facilitating VPD and on-package integration with minimal EMI concerns, (ii) employing a switching scheme that can lower the inductor footprint by 3x, and (iii) enabling soft switching to maximize switching frequency (>2MHz) while improving efficiency by >5%. Results from both the theoretical study as well as measurements from an 80W hardware prototype will be presented to substantiate the claims.
