An on-chip voltage regulator with improved load regulation and light load power efficiency

A new single stage driver circuit with improved load regulation is proposed for an on-chip voltage regulator. The improved load regulation was obtained by adding a load dependent extra current at an appropriate node of the driver circuit. Further, a load sensing circuit is proposed for improving the light load power efficiency of the on-chip voltage regulator. The circuit is implemented in 0.11 μm CMOS technology. The on-chip voltage regulator generates 1.2V from 1.8V supply. The on-chip voltage regulator load current varies from 0mA to 960mA. Simulation results showed extra offset of 268mV for single stage driver without additional circuitry, where as with additional circuitry the offset was found to be 97mV, when the load current was varied from max to min load. Results also showed up 60% power savings under light load conditions, with only 32% power increase under max load conditions. The proposed circuit is particularly useful for applications with large dynamic range of load current.