As an American and avid rights understander, it is not the 5th Amendment which this risks violating (which you did cite correctly), but the 4th Amendment, which guarantees protection from undue searches and seizures of your person, property, or effects. This is the whole reason for the warrant requirement and the reason you hear us bitching whenever something comes up that lets police or agents of the government acquire non-public access to information or property in a warrantless way.
An example: the police are investigating Mary’s death and suspect you of having planned the murder in the Notes app on your phone, so they want to get into your phone. Without a court order (warrant), you have to give them permission. With the court order, you must give the passcode and/or unlock the phone.
Now, at this point, if your passcode happened to be ‘I killed John02&’ you could argue 5th Amendment protection because divulging the information would incriminate yourself in the crime, or a different crime.