A new pulse width modulation-based digital control for single-inductor multi-output DC–DC converters with low cross-regulation

摘要

A new pulse width modulation (PWM)-based digital control for single-inductor multi-output (SIMO) DC–DC converters operating in continuous current mode (CCM) is proposed in this paper. To reduce the complexity of the control system and the hardware cost, only one digital-proportion-integration-differentiation (D-PID) compensator is used for the SIMO converters, and an idle period is introduced between each phase of the converters to reduce cross-regulation. Then, a SIMO buck DC–DC switching converter using the proposed control with two outputs is designed and implemented on a field-programmable gate array (FPGA) platform. The test results indicated that this SIMO converter can convert an input of 5V to 1.8 V and 2 V. Load transient measurements demonstrate that the cross-regulation is 0.13 mV/mA with a 300-mA load current change at output 1, and 0.04 mV/mA with a 500-mA load current change at output 2.