A Single‐Inductor Multiple‐Output DC‐DC Converter With 2.8 V–5 V Battery Voltage Supply for SoC Application in 22 nm CMOS Technology

Abstract

In advanced processes, single‐inductor multiple‐output (SIMO) DC‐DC converters with battery voltage as input face serious overvoltage problems due to low MOSFET withstand voltage. To meet the needs of SIMO converter design in advanced processes, this paper first proposes a SIMO converter with an adaptive power supply buffer (APSB) and voltage‐limiting techniques in 22‐nm CMOS. The proposed APSB technology ensures that the driving voltage of the power stage remains unchanged under the changing power supply, solving the breakdown problem caused by low MOSFET withstand voltage and simplifying the circuit design of the power stage. The proposed voltage‐limiting techniques avoid the overvoltage of the internal circuit by using a special voltage‐limiting design for the VX2 node and output voltage during startup and steady state. The proposed SIMO is designed and validated under a 22‐nm CMOS process. The input power supply range is 2.8–5 V, and the three output voltages are 0.8, 1, and 1.8 V, respectively. The maximum load for each output voltage is 250 mA. The SIMO system achieves a peak efficiency of 92.2% over the full load range.