To meet 2500 Vrms isolation (isolation level of ISO1050DUB) requirement for the CAN module, besides selecting a suitable transformer, PCB layout must be carefully designed.

PCB creepage distance is the most importance factor to achieve the 2500-Vrms isolation. For ISO1050DUB, the minimum creepage (shortest terminal to terminal distance across the package surface) is about 6.8 mm. Other components (SN6501 at the primary side and LDO at secondary side) should be kept out for this distance. Thus, a small package LDO (SOT-23 or SC70) is better to implement the creepage for small PCB size requirement of the module. The pin connections point of transformer selected also should keep the creepage. Moreover, a slot with the same width of ISO1050 should be cut underneath the transformer (isolation via air). Figure 3-6 shows the finial outline of the module, which is packaged with glue.

Figure 3-6 Front and Side Views of Isolated CAN Module