An Asynchronous Boost Converter With Time-Based Dual-Mode Control for Wide Load Range and High Efficiency in SSD Applications

A highly integrated, high-voltage dual-mode boost converter is presented for solid-state drives applications in portable devices, where standby mode efficiency with <500 mu A load is as critical as active mode efficiency with >100-mA load. To enhance efficiency in light load conditions and to achieve a wide operation load range, loss minimization by balancing conduction and switching losses is adopted, and a dynamic power-gating scheme is applied for pulse frequency modulation mode operation. Moreover, robust dual-mode operation is implemented with a time-based control scheme, which enables operation with a lower peak current for optimal loss balancing. The proposed converter is fabricated in 130-nm complementary metal-oxide-semiconductor process with an area of 1.7 mm(2). The measured efficiency for supplying 12-V output from 5.5-V input is 91% at its peak load of 40 mA and 85% with an extremely light load of 200 mu A. It also achieves a wide dynamic load range from 200 mu A to 600 mA for >85% efficiency and from 2 to 150 mA for >90% efficiency.