High-conversion-ratio buck regulator for SoC in 0.13µm digital CMOS process

Aiming to SoC (System-on-Chip) power supply in portable devices, a high-conversion-ratio buck regulator is proposed. The operation duty cycle is expanded to 100% due to the emulated current mode. The 2.5V to 4.5V input voltage range makes it ideally suited for single cell Li-Ion battery supplied devices. The range of output voltage is from 1.2V to input voltage accord to different kinds of SoC IP cores. At the same time, a high efficiency light load operation is introduced in to prolong battery lifetime. To obtain good compatibility with digital systems, the proposed buck regulator is designed in SMIC 0.13µm standard digital CMOS process (the I/O can withstand an input voltage up to 4.6V). The simulation results are consistent with expectations well.