The family has two principle parts. Similar except for output voltage, the PCA9410 is 5.0 V, while the PCA9411 is 5.25 V. Operation of the ENABLE pin varies, the basic part does not offer Forced Pass-through mode, which is only available on the ‘A’ versions. Forced pass-through changes the operation of the internal switch. On non-A versions, the high ENABLE signal activates the DC to DC boost circuit, and a low ENABLE disconnects the load. On the A versions of both parts, the high ENABLE signal actives the DC to DC boost circuit, and a low ENABLE connects the input directly to the load, with a very small voltage drop, using a 50 mΩ switch.