A New Multi-Output Structure with CRM Boost PFC Converter

This paper proposes a new multi-output structure based on a critical conduction mode (CRM) boost power factor correction (PFC) converter. A CRM boost PFC converter is widely used in small power applications. A flyback converter is generally employed for auxiliary stages in a multi-output structure due to a simple structure and low cost. However, there are many lossy components, and multiple components, such as a voltage divider, compensator, controller, and photocoupler, are also required to regulate output voltages. It will be more burden as the number of auxiliary output voltages increases. Therefore, the new multi-output structure, which does not require components for regulating auxiliary output voltage, is proposed in this paper by using an additional boost converter stage with a complementary gate signal of the CRM boost PFC converter. The analysis for a voltage gain is discussed, and the feasibility of the proposed structure is confirmed with 100-240 VAC input voltage and 400 VDC/250 W (PFC converter) and 14 VDC/12 W (auxiliary power) dual-output prototype.