you may have a look at Modularization and Dependency Management
https://sapui5.hana.ondemand.com/sdk/#docs/guide/91f23a736f4d1014b6dd926db0e91070.html
in your case :
jQuery.sap.require("sap.ui.x.y.Formatter");
sap.ui.x.y.Formatter.callFunction(something);
I hope this might help.