2013 – People Picker is not taking more than 256 Characters

I do have an InfoPath form in which I want to add a people Picker Field to validate a bulk of users that is normally more than 256 char , but I always get this alerting message (Item cannot be more than 256 characters)

I am looking for a solution avoiding any coding , however I tried a work around to feed the people picker by a multi line text field that accepts more than 256 char but it didn’t help in the validation option.