The SM91808AL from Bourns is an Automotive-Qualified Transformer that is ideal for battery management systems (BMS) applications. It has a turns ratio of 1:1, a primary voltage of up to 1000 V (DC), and a DC resistance of less than 1.4 ohms (primary and secondary). This AEC-Q200-qualified transformer is manufactured using planar technology that primarily caters to BMS signal applications. It offers a clearance distance of over 8.2 mm that allows operation at an altitude of up to 4.5 km and a creepage distance exceeding 8.2 mm with a pollution degree 2 protection rating. 

This RoHS-compliant transformer can also handle a partial discharge voltage of up to 1200 V as per the IEC 60664 standard. It is available in a surface-mount package that measures 8.5 x 17.4 mm.