BS64042CS is a flyback transformer designed for isolated power conversion in switching power supplies. It features an input voltage range of 4.5 to 60 V with a corresponding output voltage range of 6 to 28 V, and provides 2.2 kV isolation voltage with basic creepage and clearance exceeding 3 mm. The transformer has a primary inductance of 270 µH (±20%) at 250 kHz with a maximum leakage inductance of 8.5 µH, a 1:1 turns ratio, and low DC resistance values of 1.40 ohms (primary) and 2.85 ohms (secondary). Operating reliably across -40°C to +125°C, it is RoHS compliant and covered by reference designs using Analog Devices' ADP1031 chipset, making it suitable for isolated DC-DC converter designs in industrial and consumer power applications.