4.8 3-phase 6/1 switched-capacitor DC-DC boost converter providing 16V at 7mA and 70.3% efficiency in 1.1mm3

In this paper, a 3-phase switched-capacitor (SC) boost converter that uses 2 external floating capacitors to provide 16V output from a 3.3V input is presented. It achieves an efficiency of 70.3% at 7mA load current while the output ripple is 1% of the output voltage. To minimize the size of the capacitors the converter operates at a switching frequency of 6.67MHz. The chip is implemented in a 0.16μm CMOS technology and occupies 1.65mm2. The total volume of the PCB components consisting of the chip in wafer-level chip-scale package (WLSCP) and 4 external SMD capacitors (1 input, 1 output and 2 floating) is only 1.1mm3 making it attractive for space-constrained mobile applications. The volume is more than 15× smaller compared to competitive inductive converters [1-3]. The maximum thickness of the solution is 550μm.