This presentation compares two non-isolated bi-directional DC/DC converters for High-Voltage (HV) Power-Backup-Units (PBUs) – a conventional two-level synchronous buck/boost and a three-level flying capacitor buck/boost – with a focus on AI Datacenter applications. The efficiency and thermal performances are compared using hardware measurements to show the performance & trade-offs at various operating conditions seen in a HV PBU. The three-level flying capacitor buck/boost offers 41.7 % higher current handling capability due to a high full-load power-stage efficiency of >99.3% at 300Vout/10kWout, which offers potential to reduce the number of interleaved stages in a high-power design (e.g., 24kW) and improve the power (and energy) density.
