Small-Signal Modeling of Multi-Phase Trans-Inductor Voltage Regulator Modules in Datacenter Applications

In datacenters, Trans-inductor Voltage Regulator (TLVR) gains popularity as the point-of-load converter due to its superior dynamic performance. However, the investigation of its small-signal model is still untouched. To fill this gap, we first propose a small-signal model for constant on-time (COT) controlled multi-phase TLVR with external ramp compensation. An equivalent inductor model is derived to decouple the transient equivalent inductor among different phases. Accordingly, the small-signal model can be established based on the simplified equivalent circuit. The open-loop transfer function is derived using describing function method. The proposed small-signal model is validated by SIMPLIS simulation.