This article explains how to disconnect an iPad from an iPhone and how to stop syncing between devices under different circumstances.
How to Unsync Your iPad and iPhone
Your iPad, iPhone, and other Apple devices are synced when you set them up with an Apple ID. This setting is often convenient, but if you don’t want to sync data all the time, this method will completely disconnect your iPad from iCloud, and thus completely disconnect your iPad from your iPhone.
Open the Settings app on your iPad.
Tap your Apple ID username displayed at the top of the Settings menu to open your Apple ID settings.
