The HA3801-BL_ from Coilcraft is a Power Transformer with Power Rating 10 W, Primary Voltage 36 to 57 V, Secondary Voltage 3.3 V, Inductance 150 to 166.5 µH, Temperature Operating Range -40 to 125 Degree C. Tags: Surface Mount. More details for HA3801-BL_ can be seen below.