The Cellular Regulated DC Transformer (RDCX) is capable of achieving voltage regulation while maintaining high efficiency. However, low-frequency common mode (CM) noise will be introduced by the PWM regulator through inter-winding capacitance of the DCX transformer, leading to a large CM filter size. This paper proposes a novel low CM noise cellular RDCX topology with single bus multi-level regulator. Compared with the original cellular RDCX converter, CM noise can be reduced without sacrificing the efficiency and power density. A 2.3 kW prototype with 400 V input and 250–450 V output voltage range is built to verify the analysis. The proposed Cellular RDCX converter achieves over 60 dB reduction in CM noise with over 800 W/in³ power density.