Isolated converter

摘要

An isolated converter with a reduced size is disclosed. A small-sized multilayer sheet transformer (1) includes a multilayer circuit board (4) composed of a plurality of sheet substrates, coil patterns (6) of primary and secondary coils disposed coaxially on the sheet substrates, and a core member (11) disposed in a coil pattern unit (7) formed of the coil patterns. In this multilayer sheet transformer (1), a coil pattern (6) formed on the outer surface of the top layer and a coil pattern (6) formed on the outer surface of the bottom layer are for the same coil on either the primary or secondary side. In the case where the coil patterns (6) formed on the outer surfaces of the top and bottom layers of the multilayer sheet transformer (1) are for the primary coil, an isolation gap (S) is formed between the multilayer sheet transformer (1) and a circuit (3) on the secondary side to prevent an electrical breakdown between the primary and secondary sides. In the case where the coil patterns (6) formed on the outer surfaces of the top and bottom layers of the multilayer sheet transformer (1) are for the secondary coil, an isolation gap is formed between the multilayer sheet transformer (1) and a circuit (2) on the primary side to prevent an electrical breakdown between the primary and secondary sides. <IMAGE>