Fast transient response capacitorless DC-DC converter

This paper features a hybrid (switched-mode and linear-mode) and capacitorless DC-DC converter, retaining its output characteristic of the voltage source type. The converter was designed by joining a switched-mode converter and a linear amplifier connected in parallel. The benefit of this approach is that it combines the best features of both converters. In addition, the circuit presented in this paper may eliminates the need for an output capacitor, leading to an increase in the lifetime of the converter. Other characteristics of the converter include: fast response to load disturbances (for 100% step-loads: settling time < 2.0us, rise time < 100ns, overshoot <2.0%), very low output voltage ripple (< 0.1%), high efficiency (> 95%), high output signal fidelity and reliability. In steady-state, the switched-mode converter processes the majority of the energy and the linear amplifier regulates only the output voltage ripple. In addition, a model of the converter that takes into account these two different structures are presented. This paper addresses an essential protection circuit that limits current overload, acting on the current of both converters to avoid circuit damage.