8.1 A 93.8% Peak Efficiency, 5V-Input, 10A Max ILOAD Flying Capacitor Multilevel Converter in 22nm CMOS Featuring Wide Output Voltage Range and Flying Capacitor Precharging

Power delivery for compute SoCs has become a major challenge due to increasing current demands, shrinking form factors, as well as highly dynamic load patterns. Traditional inductive topologies like buck converters still require large inductances since switching frequencies cannot be increased without degrading efficiency. As a result, converter sizes are difficult to scale and transient responses are slow. On the other hand, switched capacitor converters (SCCs) are promising for small form factors and offer fast transient response since they do not require large inductors. However, SCCs can achieve high efficiency only at fixed conversion ratios, thus limiting their usage since a wide continuous range of input and output voltages are needed in SoC platforms. Hybrid converters offer the combined benefits of conventional buck and SC topologies [1]-[3]. They can provide superior power density and efficiency by reducing both inductance and capacitance requirements significantly. Since they use stacked low voltage transistors like SCCs, higher switching frequencies can be achieved without degrading efficiency. In addition, soft-charging of the flying capacitors through the inductor eliminates charge-sharing losses present in pure SCCs.