The 22-year-old, who has just signed a new contract with Spurs keeping him at the club until 2014, will help bolster the Addicks up front.
"Jonathan is a player we have kept an eye on this season in a number of games. I saw him when he played against us and he has an eye for a goal.
"He is a player full of potential and it is a chance for us to have a good look at him. Hopefully he will come into the group and make an impact."
The striker has had loan spells at Crystal Palace and Yeovil Town.