A Fast SIMO Converter for Command-Directed IoT Nodes With State-Driven Priority Sequencing and Delay-Adjusted Fixed Window Hysteretic Control Using Constant Current-Peak Sequential DCM-CCM Operation

This work presents a single-inductor multiple-output (SIMO) converter to achieve a fast transient response using a low-profile inductor for powering the command-directed Internet of Things (IoT) nodes. The multiple outputs are sequentially charged and regulated afterward by the proposed state-driven priority sequencing and the delay-adjusted fixed window (DAFW) hysteretic controller to keep the output transient ripple low. Also, the multiple outputs are serviced using the proposed constant current-peak sequential discontinuous conduction mode (DCM)-continuous conduction mode (CCM) (CCPS-DCM-CCM) operation to obtain zero cross-regulation and a fast transient response. To make a better trade-off between light load efficiency and fast transient response at the high load, the proposed converter operates in two different command-directed modes, namely CCPS-DCM switching at \sim 70 kHz for a load range of 10 ~\mu A-1 mA and CCPS-DCM-CCM operating at \sim 3.1 MHz for a load range of 1-40 mA. The proposed SIMO converter is designed in a standard 180-nm CMOS technology to generate three regulated outputs of 0.9, 1.2, and 1.5 V. In the measured results, the converter shows an output transient ripple