A single-inductor dual-output (SIDO) based power management with adaptive bus voltage (ABV) modulation and zero cross-regulation (CR) operation is proposed in this paper. To achieve the advanced power supply function in system-on-a-chip (SoC), the N-type low-dropout LDO regulator (N-LDR) is placed behind the SIDO converter to suppress voltage ripple and to eliminate the CR problem of SIDO converter. Besides, the proposed ABV modulator can adjust the output voltage of the SIDO converter as well as the dropout voltage on N-LDR according to the output load conditions. Thus, the power loss can be effectively minimized so as to enhance the power efficiency. Output voltage regulation and load transient response can be guaranteed simultaneously. The chip was fabricated by 40 nm CMOS process. Experimental results show the maximum 20 % energy saving in the proposed power management with a peak efficiency of 86 % and the high power supply rejection of 45dB at 1 MHz in N-LDR for SoC integration.