BM1Q104FJ Quasi-Resonant Control DC-DC Converter ROHM Semiconductor BM1Q104FJ Quasi-Resonant Control DC-DC Converter provides an optimum solution for applications that include an electrical outlet. The quasi-resonant operation of the BM1Q104FJ enables soft switching and helps keep EMI low. As the MOSFET for switching and current detection resistors are external devices, a high degree of design freedom is achieved. The BM1Q104FJ integrates an HV starter circuit that tolerates high voltage, contributing to the device's low power consumption and high-speed starting capability.