The MHFS31209 from Cosel is a DC to DC Converter with Input Voltage 4.5 to 18 V, Output Voltage 1 9 V, Output Current 1 0.33 A, Output Power 2970 mW, Isolation Voltage 4200 Vdc. Tags: Through Hole, Buck-Boost. More details for MHFS31209 can be seen below.