Photocoupler package shapes and dielectric strength must be in accordance with safety standards. Therefore, there are restrictions on package design of photocouplers, unlike other semiconductor products.
- Creepage distance: The shortest distance between two conductors (input-output) along the surface of insulator
- Clearance: The shortest distance between two conductors in the air
- Insulation thickness: The minimum thickness of the insulator between two conductors
- Isolation voltage: Isolation voltage between two conductors. The UL standard specifies this voltage as a voltage at which isolation is not destroyed by application of AC for one minute.
For Toshiba photocouplers, data with values to which these are applied are provided to individual technical documents.