A High Efficiency, Extended Load Range Boost Regulator Optimized Forenergy Harvesting Applications

A small, low power bootstrapped boost regulator is introduced that can start upwith an input voltage of 240mV and achieve a maximum efficiency of 96%. The proposed circuituses two separate control schemes for startup and steady-state operation. A xed-frequencyoscillator is used to initially start up the circuit and raise the output voltage. Once the outputvoltage has reached a level adequate to bias the internal circuitry, a constant-on-time stylehysteretic control scheme is used, which helps increase system efficiency compared to using aconventional Pulse-Width-Modulated control scheme. While maintaining a high efficiency, theproposed circuit only requires 3 external components|2 capacitors (input and output) and aninductor. The e ectiveness of this approach is shown through Spectre simulation results.