Winforms C# TextBox binding not on every key stroke and on validating but without losing focus

Question

In my app I use a lot of usercontrols. For binding I have used until now OnPropertyChanged but after that we realized that is not efficient in cases where the user types 5 or more characters then OnPropertyChanged event is fired after each character change. What I have tried is to change the binding to be OnValidating but this approach has one disadvantage it only updates the value when the control lose focus and for a better user experience it would be better to have the update even if the focus is not lost. I know that another alternative would be to use a timer with a predefined delay value but I'm not very confident using this approch. What else can I try in order to implement this scenario? Thanks a lot for all your help.