An Asymmetric Dual Output On-Chip DC-DC Converter for Dynamic Workloads

We propose a novel two-stage hybrid on-chip DC-DC converter targeting low power applications with multiple supply voltage domains and dynamic workloads. The converter has a nominal input voltage of 1.2V and generates two asymmetrically regulated output voltages simultaneously. The high-power output channel provides voltages ranging from 0.3V to 1.1V and up to 12mA load current; on the other hand, the low-power output channel delivers voltages varying from 0.3V to 0.5V with up to 1mA load current. The high-power output is able to respond to load transition requests with a peak voltage slew rate of 16V/ mu s and maximum voltage ripple of 49mV. During load transitions at the high-power channel, the low-power output voltage with fixed load remains stable with less than 7.6% ripples and a worse case droop 4'45 mV. In addition, when load transitions are requested at both output channels simultaneously, there are no observable voltage droops/spikes at the outputs; thus, cross regulations are significantly reduced. Even with input voltage glitches, additional voltage spikes/droops at each output are less than 5%. Peak power efficiency achieved is 73%.