Reset-sensing quasi-V2 single-inductor multiple-output buck converter with reduced cross-regulation

This paper proposes a reset-sensing quasi-V² single-inductor multiple-output (SIMO) converter with minimal cross-regulation. The conventional quasi-V² sensing scheme in SIMO converters suffers from serious cross-regulation which is primarily induced by the load differentiation with unbalanced loads. It is shown that the proposed reset-sensing quasi-V² control scheme can significantly reduce cross-regulation by completely discharging the feed-forward sensing node to zero volts during the idle phase in Discontinuous Conduction Mode (DCM). The cross-regulation with the conventional quasi- V² single-inductor dual-output (SIDO) converter for a load current step of 150 mA is experimentally verified to be more than 1.25 mV/mA. By employing the proposed quasi- V² control method, the experimental results demonstrate that the cross-regulation for a load current step of 150 mA is significantly reduced to within 0.087 mV/mA. Hence, with the proposed scheme, a load transient in one output will have a minimal effect on the DC operating point of another output. This enables separate current control at each individually-driven output of a SIMO converter.